October 2022   |   Volume 20   |   Issue 7
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Feline Enteric Coronavirus & Feline Infectious Peritonitis

FIP effusion

in this issue

in this issue

Feline Enteric Coronavirus & FIP

Limb Swelling in an Intact Boerboel

Intermittent Back Pain in a Young Dog

Immune-Mediated Thrombocytopenia in a Dog

Drugs Used for Emesis Induction in Dogs

Drugs Used for Emesis Induction in Cats

Differential Diagnosis: Elevated ALP

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Antech CB October 2022
Antech CB October 2022

Feline Enteric Coronavirus & FIP

Jarod M. Hanson, DVM, PhD, DACVPM, DABT, University of Maryland

Infectious Disease

|Peer Reviewed

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Feline Enteric Coronavirus & FIP

Feline enteric coronavirus (FECV) is an Alphacoronavirus, unlike severe acute respiratory sydrome coronavirus 2 (ie, SARS-CoV-2) and canine respiratory coronavirus, which are Betacoronaviruses.1 FECV typically causes mild, often subclinical GI illness through infection of enterocytes2; however, a multifactorial process that relies on viral mutations (eg, spike gene mutations3,4) in the host during persistent infection can cause FECV to lose tropism for enterocytes and preferentially infect monocytes and macrophages. This change induces a dysregulated immune response, leading to FIP. The cause of the viral mutations is unclear.

Serotypes

Feline coronavirus has 2 serotypes, both of which can cause the wet or dry form of FIP. Serotype I viruses likely originated in the United States and spread internationally as the predominant serotype.5,6 Type I viruses demonstrate a lack of crossprotection with serotype II strains, complicating vaccine development (see Prevention & Treatment).7

Transmission

FECV is transmitted via multiple routes, including fecal–oral, blood, and other body fluids.8 Vertical transmission from queens to kittens is common and likely occurs before 16 weeks of age.8 Sexual transmission from intact males is unlikely; seropositive males may have FECV viruses or viral fragments in testicular tissue, but it is not clear if or when this material may be shed in the semen.9

Although most cats become infected with FECV, long-term disease is uncommon. FIP is not caused by transmission of FECV alone; persistent infection and viral mutations that allow the virus to preferentially infect monocytes and macrophages is necessary. Unmutated FECV can infect monocytes and macrophages but preferentially infects enterocytes.10 Risk factors for FIP include stress, age, immunosuppressive infections, and genetic predisposition.11-13 FIP occurs in ≈5% to 10% of cats with FECV and <1% of cats admitted to veterinary hospitals.14

Clinical Signs

FIP typically occurs in young or old cats but can occur in cats of any age and affects both domestic and wild felid species.2,15 

The wet form of FIP is characterized by cavitary effusion (Figures 1 and 2) and can cause pyogranulomatous inflammation in one or more organs. The dry form typically results in variably sized pyogranulomas in affected organs and does not cause cavitary effusion.2 Lesions can include atypical presentations (eg, ocular, neurologic, ileocolic, rhinitis).2,16

Pathogenesis

Infected monocytes and macrophages recruit additional monocytes, macrophages, and neutrophils via cytokines and inflammatory mediators (eg, vascular endothelial growth factor, matrix metalloproteinase-9) that cause enhanced vascular permeability.17,18 Type III and IV hypersensitivity reactions may also increase vascular permeability and/or granuloma formation.2

Diagnosis

Diagnosis via serology or reverse transcriptase PCR (RT-PCR) of infectious materials can be difficult, as subclinical cats may have high titers and severely ill cats may have no titers. Cats with FIP typically exhibit higher coronavirus titers than cats with FECV that are not persistently infected.18

Cats are often infected with multiple variants of FECV, most of which are benign and create false-positive results if primers do not adequately target likely mutation sites. PCR should therefore be specific enough to identify FIP variants without missing unique mutations. These mutations can also cause FIP but are outside the boundaries of PCR primers used on the S gene, which can generate false-negative results.3,19 RT-PCR results should be verified via biopsy with immunohistochemistry.20 Sequencing the S gene allows all mutations in the S gene to be identified but is not widely available; results should be interpreted in conjunction with other diagnostic results. 

Surgical biopsy with histopathology or fine-needle aspiration with cytology of affected organs is often used with immunohistochemistry to support diagnosis and determine disease stage.21 Full fluid analysis of cavitary effusions associated with FIP commonly demonstrates yellow, viscous fluid with an elevated protein concentration (>3.5 g/dL) and disproportionately low cell count.22 Fluid analysis in addition to other diagnostics (eg, serology, RT-PCR, fine-needle aspiration) performed on a variety of tissues can increase the probability of confirming diagnosis of FIP based on cumulative test results, signalment, and patient history.3 Histopathology, immunohistochemistry, and RT-PCR have 40% to 85% sensitivity and 83% to 100% specificity (depending on tissue type), reinforcing the need for a multifaceted diagnostic approach.20,21

Prognosis

The mortality rate of FIP has been >95% but is likely decreasing with new treatment options.23,24

Prevention & Treatment

FIP vaccines are available but not recommended by AAFP or AAHA due to lack of crossneutralization (vaccine contains serotype II virus only).7,25 In addition, the vaccine is labeled for administration at 16 weeks of age, at which point kittens are likely already infected by queens.7 Antibody-dependent enhancement of disease has been observed experimentally but has not been noted during natural infection or vaccine field studies.25 Despite these concerns, vaccination may be clinically useful in limited situations (eg, catteries, other dense populations when introducing naive cats).25

Control of FECV and FIP via isolation of persistently infected cats to interrupt the transmission cycle can be attempted but is not likely to be effective in multicat environments. 

Experimental antiviral drugs have some efficacy for treatment of FIP,26-30 and nonnucleoside analogues (eg, ERDRP-0519, GS-441524, remdesivir) are emerging as possible treatment options.27,31,32 

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Dasuquin CB October 2022

Limb Swelling in an Intact Boerboel

Michael Hung, DVM, Texas A&M University

Carly Patterson, DVM, DACVIM (SAIM), Texas A&M University

Infectious Disease

|Peer Reviewed

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Limb Swelling in an Intact Boerboel

Clinical History & Signalment

Hercules, a 200.6-lb (91-kg), 15-month-old intact male Boerboel, was presented to a referral clinic for a swollen left hock of 5 months’ duration. Swelling was seen after Hercules had been boarded. He was purchased from a breeder in Illinois at 9 months of age and lived in northeast Texas. He was otherwise healthy.

An immunosuppressive dosage of prednisone (40 mg/m2 PO every 24 hours, tapered over 15 days) and amoxicillin/clavulanic acid (9.9 mg/kg PO every 12 hours for 10 days) were administered. Carprofen (2.2 mg/kg PO every 12 hours for 14 days) was given after prednisone had been tapered with a 72-hour washout period. No improvement was seen. Radiographs of the affected leg taken by the referring clinician were unremarkable.

Physical Examination

On physical examination at the referral clinic, Hercules was bright, alert, and responsive. Initial temperature was elevated (103.2°F [39.6°C]), but recheck temperature was normal (101.4°F [38.5°C]). He was weight-bearing on all limbs. The left pes and tarsus were diffusely swollen with nonpitting edema (Figure 1). The dorsal tarsus was thickened, and the third digit was swollen circumferentially with severe erythema and crusting at the level of the claw (Figure 2). No warmth was appreciated. Hercules appeared to mildly resist manipulation of the toe but did not seem otherwise painful. The left popliteal lymph node was mildly enlarged and firm. Diffuse scaling was present over the tail base, and crusting papules and collarettes were distributed asymmetrically over the trunk, tail base, and extremities. The remainder of the physical examination was unremarkable.

Edematous appearance of the left tarsus and swollen third digit, especially compared with the contralateral limb
Edematous appearance of the left tarsus and swollen third digit, especially compared with the contralateral limb

FIGURE 1 Edematous appearance of the left tarsus and swollen third digit, especially compared with the contralateral limb

FIGURE 1 Edematous appearance of the left tarsus and swollen third digit, especially compared with the contralateral limb

Enlargement, erythema, and crusting at the distal aspect of the third digit at the level of the claw
Enlargement, erythema, and crusting at the distal aspect of the third digit at the level of the claw

FIGURE 2 Enlargement, erythema, and crusting at the distal aspect of the third digit at the level of the claw

FIGURE 2 Enlargement, erythema, and crusting at the distal aspect of the third digit at the level of the claw

Diagnosis

Differential diagnoses for a single swollen limb include increased hydrostatic pressure from arteriovenous fistula or obstruction caused by trauma, foreign body, or neoplasia; increased capillary permeability from envenomation, trauma (including foreign body), burn, or infectious cellulitis; and lymphatic drainage dysfunction from lymphangiosarcoma or lymphedema (see Take-Home Messages). 

CBC showed a mature neutrophilia (17,864/µL; reference interval, 3,000-11,500/µL), and serum chemistry profile revealed mildly increased globulin (4.2 g/dL; reference interval, 1.7-3.8 g/dL). 

Radiographs of the left pelvic limb revealed soft tissue swelling of the digit and tarsus with no bony involvement, and cytology of the left popliteal lymph node showed reactive lymphoid hyperplasia. Fundic examination results and thoracic radiographs were unremarkable. 

The affected digit was clipped, cleaned, and examined with the patient under sedation; ulcerated wounds were present, but no draining tract was noted (Figure 3). Cytology was not performed due to high likelihood of contamination because of the location of the wound and because bacteria in the region were likely significantly reduced during preparation. Surgical biopsies with the patient under general anesthesia were planned.

Ulcerated lesions on the digit after hair was clipped
Ulcerated lesions on the digit after hair was clipped

FIGURE 3 Ulcerated lesions on the digit after hair was clipped

FIGURE 3 Ulcerated lesions on the digit after hair was clipped

Hercules was anesthetized for lymphangiogram, surgical biopsies of the dorsal tarsal and digital skin and subcutaneous tissues, and pelvic limb CT (to assess for subtle bony lesions and vascular malformation). Lymphangiogram was normal. Tissue from the digit was submitted for aerobic and anaerobic culture for Nocardia spp and Actinomyces spp growth; one colony of Staphylococcus epidermidis (likely a contaminant) was present. Histopathology of the digit showed severe, regionally extensive, chronic pyogranulomatous panniculitis with rare intralesional yeast most consistent with Blastomyces spp (Figure 4). Mild, diffuse, chronic perivascular lymphoplasmacytic panniculitis of the dorsal tarsus was also noted, likely secondary to Blastomyces spp infection.

Histopathology showing multifocal-coalescing pyogranulomatous dermatitis and panniculitis and intralesional fungal yeast (arrow). Hematoxylin and eosin stain, 60× magnification. Image courtesy of Dominique Wiener, Dr.med.vet, PhD, DECVP
Histopathology showing multifocal-coalescing pyogranulomatous dermatitis and panniculitis and intralesional fungal yeast (arrow). Hematoxylin and eosin stain, 60× magnification. Image courtesy of Dominique Wiener, Dr.med.vet, PhD, DECVP

FIGURE 4 Histopathology showing multifocal-coalescing pyogranulomatous dermatitis and panniculitis and intralesional fungal yeast (arrow). Hematoxylin and eosin stain, 60× magnification. Image courtesy of Dominique Wiener, Dr.med.vet, PhD, DECVP

FIGURE 4 Histopathology showing multifocal-coalescing pyogranulomatous dermatitis and panniculitis and intralesional fungal yeast (arrow). Hematoxylin and eosin stain, 60× magnification. Image courtesy of Dominique Wiener, Dr.med.vet, PhD, DECVP

CT showed soft tissue thickening of the third digit and distal portion of the left limb consistent with edema or cellulitis and left popliteal lymphadenomegaly with no evidence of a mass, foreign body, or vascular malformation.

Urine quantitative antigen test result was positive for Blastomyces spp (0.48 ng/mL; quantifiable range, 0.2-14.7 ng/mL).

Illinois is an endemic state for blastomycosis. Hercules was likely infected via inoculation (based on localized signs) while still with the breeder, and development of clinical signs after boarding was likely incidental. Stress may have resulted in immunocompromise that contributed to infection. 

Cutaneous lesions (ie, collarettes, pustules) on the trunk, tail base, and extremities were consistent with presumed clinical bacterial pyoderma.1,2

DIAGNOSIS:

BLASTOMYCOSIS

TREATMENT AT A GLANCE

  • Oral itraconazole is the first-line treatment for blastomycosis. 
  • Fluconazole can have similar efficacy as and is less expensive compared with itraconazole; however, longer treatment periods may be needed.
  • Liver enzymes should be evaluated monthly with azole treatment. Clinically affected areas should be checked monthly to monitor progression or regression of disease.
  • Serial urine antigen tests can be performed every 3 months and can indicate successful treatment. A decrease in antigen concentration is consistent with effective treatment.
  • Fungal infections require prolonged treatment over months. Relapse may occur, even with appropriate treatment. 

Treatment & Management

Fluconazole (11 mg/kg PO every 24 hours) was administered based on the patient’s large weight (due to cost) and because severe systemic disease was not present (see Treatment at a Glance). Collarettes and scaling were considered secondary to presumptive superficial bacterial pyoderma and treated topically with chlorhexidine gluconate 2%/miconazole nitrate 2%/tris-EDTA shampoo.

Blastomycosis can exhibit testicular tissue tropism.3 Neuter was recommended, especially due to possible relapse, but the owner declined.

Prognosis & Outcome

At the one-month recheck, neutrophilia (12,000/µL; reference interval, 3,000-11,500/µL) and hyperglobulinemia (4 g/dL; reference interval, 1.7-3.8 g/dL) were improved, the digit was no longer ulcerated, and swelling and erythema had improved; however, the digit and hock were still enlarged (Figure 5). Treatment was continued.

Improved appearance of dermatologic lesions on the digit after one month of treatment with fluconazole
Improved appearance of dermatologic lesions on the digit after one month of treatment with fluconazole

FIGURE 5 Improved appearance of dermatologic lesions on the digit after one month of treatment with fluconazole

FIGURE 5 Improved appearance of dermatologic lesions on the digit after one month of treatment with fluconazole

At the 2-month recheck, the owner reported Hercules was doing well, but the digit and foot remained swollen (Figure 6). ALT was elevated (258 U/L; reference interval, 10-125 U/L), which was attributed to liver enzyme activation due to fluconazole therapy, and the dose was reduced by 40%. A 3-month recheck was recommended to evaluate antigen concentrations, but the patient was not returned. 

Hercules’ overall prognosis was positive, but prognosis for return to a normal digit and tarsus was guarded.

Affected tarsus after 2 months of treatment. Erythema and swelling had improved, but the digit and tarsus remained enlarged.
Affected tarsus after 2 months of treatment. Erythema and swelling had improved, but the digit and tarsus remained enlarged.

FIGURE 6 Affected tarsus after 2 months of treatment. Erythema and swelling had improved, but the digit and tarsus remained enlarged.

FIGURE 6 Affected tarsus after 2 months of treatment. Erythema and swelling had improved, but the digit and tarsus remained enlarged.

Discussion

Blastomycosis is a systemic disease caused by Blastomyces dermatitidis, a broad-based dimorphic fungus found in the soil around the Ohio and Mississippi River valleys, the Great Lakes, and southeastern states; the primary route of infection is the respiratory tract. Common sites of disseminated infection include the skin, subcutaneous tissue, eyes, bones, lymph nodes, brain, and testes.1,2

Dermatologic signs can be seen with blastomycosis; 30% to 50% of dogs have cutaneous signs at diagnosis.1,4 Incidence of dogs presented solely for localized cutaneous signs is not well described, although one study noted only 13% of dogs with blastomycosis had no radiographic pulmonary changes.4 Thoracic radiographs were unremarkable in this case. 

Diagnosis is made by identifying the organism via cytology, histopathology, culture, or antigen testing.5 Histoplasmosis should be ruled out in patients that live in states where both Histoplasma spp and Blastomyces spp are endemic, as Histoplasma spp can cross-react with Blastomyces spp quantitative antigen testing on both urine and serum.5 Cytology of the affected digit in this case could have resulted in diagnosis, but more extensive sampling under anesthesia was preferred.

Definitive diagnosis involves respiratory sampling, which is not often pursued without other evidence of involvement. In humans, primary cutaneous blastomycosis is rare, and differentiation from secondary cutaneous blastomycosis with negative thoracic radiography is difficult.6,7

Poll

When do you most often perform cytology of skin lesions for diagnosis?

Itraconazole is the treatment of choice for blastomycosis, but amphotericin B can be administered parenterally in dogs with severe disease or CNS disease or in dogs refractory to treatment.1,8 Fluconazole can also be used but is considered less effective than itraconazole for non-CNS disease in humans.8-10 One study found similar efficacy in dogs administered fluconazole or itraconazole; fluconazole treatment had longer duration but was less expensive.11

Treatment generally lasts ≥3 months and should be continued 1 month beyond resolution of clinical signs. Radiography should be performed at 4- to 6-week intervals if abnormalities are present on thoracic imaging. Liver enzymes should be monitored with any azole treatment (generally at 2 weeks, then at 4- to 6-week intervals). Urine antigen tests can help monitor disease progression and can be performed every 3 months; antigen reduction is associated with appropriate treatment. Remission can be determined by normal physical examination and normal or static imaging (eg, thoracic radiographs) findings.12 Approximately 50% to 75% of dogs with blastomycosis respond to treatment, but 20% can relapse, usually within one year.12-14

One study found dogs with absent or mild pulmonary radiographic signs and low Blastomyces spp antigen concentrations survived ≥1 year after diagnosis.15 Chronic inflammation, persistent edema, and panniculitis can result in fibrosis, similar to chronic lymphedema.16,17 Persistent swelling may indicate persistence of disease, as most fungal infections require treatment for >2 months.1,12,15

TAKE-HOME MESSAGES

  • A problem-based approach with attention to anatomy (including vascular and lymphatic causes) and localization of signs should be used in patients with limb swelling.
  • Advanced imaging may be needed to rule out lymph node obstruction and vascular malformation.
  • Thorough examination for infectious etiologies, including histopathology and tissue culture, should be performed in patients with limb swelling.  
  • Blastomycosis is a disseminated disease in dogs; localized infections are possible. Most patients are presented with predominantly respiratory and/or cutaneous signs.
  • Histoplasmosis should be ruled out in patients with a positive Blastomyces spp quantitative antigen test result, and blastomycosis should be ruled out in patients with a positive Histoplasma spp quantitative antigen test result in regions endemic to both of these fungi.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Arthrex CB October 2022

Immune-Mediated Thrombocytopenia in a Dog

Andrew Bugbee, DVM, DACVIM, University of Georgia

Internal Medicine

|Peer Reviewed

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Immune-Mediated Thrombocytopenia in a Dog

Kate, a 5-year-old spayed German shepherd dog, is presented for abdominal bruising, acute-onset discolored stool (ie, black) of 24 hours’ duration, and recent stranguria with pollakiuria. One year prior, she had a UTI caused by Escherichia coli that was treated with a 10-day course of amoxicillin (15 mg/kg PO every 8 hours). Kate receives monthly heartworm, flea, and tick preventives and is current on vaccines. She was vaccinated 7 months prior to presentation, at which time, point-of-care ELISA test results for heartworm, borreliosis, ehrlichiosis, and anaplasmosis were negative. She is otherwise healthy.

On physical examination, Kate is quiet but alert and responsive. BCS is 4/9. Petechiation of the mucous membranes with multiple petechiae and ecchymoses on the ventral abdomen are the only abnormal physical examination findings (Figure 1). Melena is observed when the patient defecates (Figure 2).

Petechiation and ecchymoses on the ventral abdomen. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC
Petechiation and ecchymoses on the ventral abdomen. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC

FIGURE 1 Petechiation and ecchymoses on the ventral abdomen. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC

FIGURE 1 Petechiation and ecchymoses on the ventral abdomen. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC

Melenic stool seen during examination. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC
Melenic stool seen during examination. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC

FIGURE 2 Melenic stool seen during examination. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC

FIGURE 2 Melenic stool seen during examination. Image courtesy of Benjamin Brainard, VMD, DACVAA, DACVECC

Abnormalities on CBC include moderate regenerative anemia (28%; reference interval, 41.2%-54.8%), severe thrombocytopenia (<10,000/µL; reference interval, 226,000-424,000/µL), and mild leukocytosis characterized by mature neutrophilia (10,331/µL; reference interval, 2,700-8,500/uL). Blood smear is assessed for concurrent hemolysis, but no spherocytosis is noted; saline agglutination test is negative. Serum chemistry profile results are unremarkable. Free-catch urinalysis reveals numerous WBCs and bacteriuria. 

Thoracic and abdominal radiography and abdominal ultrasonography are performed to rule out concurrent disease (eg, neoplasia) as a secondary cause of platelet destruction, but results are unremarkable. A comprehensive vector-borne infectious disease panel (including Anaplasma spp, Babesia spp, Bartonella spp, Ehrlichia spp, and hemotropic Mycoplasma spp) is seronegative and PCR negative for all assessed organisms.

Without an identifiable precipitating cause, Kate is presumptively diagnosed with primary immune-mediated thrombocytopenia (ITP). Antiplatelet antibody testing is available but is not pursued, as the results would not affect clinical decision-making in this case.

Which of the following drugs would be appropriate for this patient?*

Do Not Use Proceed with Caution Safe

The following represents the best responses based on drug metabolism, pharmacokinetics, species, diagnostic differentials, clinical and laboratory data, and other pertinent findings.

PREDNISONE

Correct ResponseSafeGlucocorticoids (eg, prednisone) are considered first-line therapy to stop platelet destruction in patients with primary ITP. Prednisone suppresses multiple components of abnormal immune responses, but long-term administration of immunosuppressive dosages (≥2 mg/kg PO, IM, or IV every 24 hours) is associated with adverse effects (eg, iatrogenic hyperadrenocorticism, GI ulceration, ligamentous injury). Prednisone is thus often administered with adjunctive immunosuppressants to facilitate more rapid tapering while controlling clinical signs; however, no multiple-agent protocol for ITP has been consistently associated with a survival benefit or lower relapse rate as compared with prednisone alone.1

CARPROFEN

Correct ResponseDo Not UseCarprofen is a cyclooxygenase-inhibiting NSAID not indicated for immune suppression, which is necessary for patients with ITP. NSAIDs should not be administered concurrently with glucocorticoids because of increased risk for adverse effects (eg, GI ulceration). NSAIDs are also contraindicated in this patient because they inhibit platelet function, which could worsen clinically apparent mucosal bleeding secondary to thrombocytopenia.2

CYCLOSPORINE

Correct ResponseProceed with CautionCyclosporine is a calcineurin inhibitor immunosuppressant typically coadministered with glucocorticoids to suppress lymphocyte proliferation in patients with ITP. Dogs should be given the modified, microemulsified formulation to ensure adequate bioavailability. Although a benefit for increased survival has not been consistently shown compared with glucocorticoids alone, cyclosporine may allow faster withdrawal of glucocorticoid therapy to reduce risk for adverse effects.1 GI adverse effects are most common; gingival hyperplasia and papillomatosis are less common.3 A possible predisposition to lymphoma has only been reported in one dog.4 Cyclosporine use in patients with ITP also receiving vincristine may cause predisposition to neutropenia; additional monitoring for myelosuppression is warranted when these drugs are administered concurrently.5

MYCOPHENOLATE MOFETIL

Correct ResponseProceed with CautionMycophenolate mofetil has been increasingly used as an adjunctive immunosuppressant (most often with glucocorticoids) and is metabolized to mycophenolic acid, which inhibits inosine monophosphate dehydrogenase necessary for purine synthesis and lymphocyte proliferation.6 GI adverse effects are common; myelosuppression, hepatotoxicity, and dermatologic reactions are less common but may require additional therapeutic monitoring.7 In humans, concurrent administration of mycophenolate mofetil and antacids impaired immunosuppressive efficacy, as mycophenolate mofetil requires an acidic environment for conversion into active metabolites.8 Although the significance of this interaction has not been evaluated in dogs, these drugs should be administered separately when used concurrently.

AZATHIOPRINE

Correct ResponseProceed with CautionAzathioprine is an antimetabolite immunosuppressant often used in conjunction with glucocorticoids for treatment of immune-mediated diseases and has been associated with hepatotoxicity and myelosuppression, especially when initial therapeutic doses are administered for prolonged periods.1,9 Reported tapering schedules should therefore be followed, and CBC and liver values should be intermittently monitored during therapy. German shepherd dogs were overrepresented in a study of azathioprine-associated toxicoses, especially development of hepatotoxicity.9

VINCRISTINE

Correct ResponseSafeVincristine is a vinca alkaloid chemotherapeutic agent that disrupts microtubules in rapidly dividing cells. Vincristine administered at low doses increases circulating platelets by accelerating fragmentation from megakaryocytes.10 These prematurely released platelets are functional when entering circulation, supporting vincristine as a first-line therapy for patients with ITP.11

Vincristine can cause extravasation injury; careful catheter placement is thus necessary prior to administration. Myelosuppression is also a known risk, and further dose reduction should be considered in dogs weighing >33.1 lb (15 kg), as the dosage for thrombocytopenia (0.02 mg/kg IV once) may fall in the oncologic range (0.5-0.75 mg/m2 IV once weekly). Risk for myelosuppression is also increased in dogs with the multidrug sensitivity gene (MDR1 gene, also known as ABCB1 gene) or when vincristine is used concurrently with cyclosporine.4,12

FAMOTIDINE

Correct ResponseDo Not UseMost patients with ITP and evidence of active hemorrhage lose blood across intact mucosal surfaces in the absence of overt ulceration. Antacids are often administered to increase gastric pH for protective purposes, as high-dose glucocorticoids increase risk for ulceration. Famotidine is an over-the-counter histamine type-2 receptor antagonist, and oral administration of this drug is ineffective for increasing gastric pH to a sustained level for therapeutic benefit.13,14 Famotidine is therefore not recommended when more effective oral acid-suppressing therapies are available.1,15

OMEPRAZOLE

Correct ResponseProceed with CautionOmeprazole is an over-the-counter antacid proton pump inhibitor. Oral omeprazole administration results in higher gastric pH than famotidine and is therefore recommended for gastroprotection in patients with GI ulceration.13,16 Omeprazole administration could be considered in patients with ITP for GI bleeding; however, bleeding is believed to be related to thrombocytopenia, with ulceration being less likely. Omeprazole should be discontinued once melena resolves. In addition, acid suppression may impact drug metabolism and reduce immunosuppression efficacy if omeprazole is administered concurrently with mycophenolate.8

AMOXICILLIN

Correct ResponseSafeAmoxicillin is a beta lactam antibiotic recommended for empiric treatment of clinical bacterial UTI.17 This therapy should be initiated while urine culture is pending; however, sterile sample collection via cystocentesis is unlikely in this thrombocytopenic patient. Based on history of infection and therapeutic response, therapy should be initiated because the patient is showing clinical signs and will soon be immunosuppressed. Therapeutic monitoring involves assessing improvement in clinical signs and a urine culture to document infection clearance once the platelet count is recovered.

TRIMETHOPRIM/SULFADIAZINE

Correct ResponseDo Not UseTrimethoprim/sulfadiazine is a potentiated sulfonamide antibiotic that may be used for empiric treatment of clinical bacterial UTI17; however, this class of antibiotics is associated with possible idiosyncratic autoimmune adverse effects, including thrombocytopenia.18

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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pHnotix CB October 2022

Prevalence of GI Ulcers in Dogs Treated with Long-Term NSAIDs

Sue Hudson Duran, RPh, MS, PhD, DICVP, FSVHP, FACVP, Auburn University

Pharmacology & Medications

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Prevalence of GI Ulcers in Dogs Treated with Long-Term NSAIDs

In the literature

Mabry K, Hill T, Tolbert MK. Prevalence of gastrointestinal lesions in dogs chronically treated with nonsteroidal anti-inflammatory drugs. J Vet Intern Med. 2021;35(2):853-859.

FROM THE PAGE …

Gastroduodenal ulceration and perforation are potential complications of NSAIDs; however, the prevalence of chronic GI injury associated with administration in dogs is unknown. 

This prospective study sought to determine the prevalence of GI mucosal erosions in 14 client-owned medium- and large-breed dogs treated with an NSAID for ≥30 days. An additional 11 client-owned dogs were retrospectively evaluated as controls. 

Video capsule endoscopy was performed to record GI transit time and presence of mucosal lesions. Images could not be obtained from 2 dogs in the NSAID group. Of the remaining 12 dogs, 10 exhibited GI erosions. In the control group, 3 dogs had GI lesions. More erosions were detected in dogs receiving NSAIDs than those in the control group, and none of the dogs with lesions had reported clinical signs. GI transit time did not appear to be prolonged in dogs treated with NSAIDs.

… TO YOUR PATIENTS

Key pearls to put into practice:

1

Dog owners should be informed of the potential for GI ulceration in dogs receiving long-term NSAID treatment. Information sheets that detail potential adverse effects are recommended and available online from manufacturers of NSAIDs approved for use in dogs.

2

Regular recheck examinations are needed for dogs receiving chronic NSAID therapy. A thorough physical examination with standard laboratory evaluation, including CBC, serum chemistry profile, and urinalysis, is recommended. Renal and hepatic function and albumin levels should be monitored for necessary dosage adjustments with long-term NSAID use. NSAIDs are highly protein bound; dosage adjustments or changes in therapy should be considered in patients with low albumin.

3

Only NSAIDs specifically labeled for use in dogs should be administered. Proper dosage adjustments and frequent follow-ups are important. Owners should be instructed to never administer additional doses or increase the frequency of administration without asking the clinician.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Hill's Derm CB October 2022

Robenacoxib for Pain Management in Cats with Chronic Musculoskeletal Disease

Alonso Guedes, DVM, MS, PhD, DACVAA, University of Minnesota

Pharmacology & Medications

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Robenacoxib for Pain Management in Cats with Chronic Musculoskeletal Disease

In the literature

King JN, Seewald W, Forster S, Friton G, Adrian DE, Lascelles BDX. Clinical safety of robenacoxib in cats with chronic musculoskeletal disease. J Vet Intern Med. 2021;35(5):2384-2394. 

FROM THE PAGE …

Pain management in cats with chronic musculoskeletal disease (eg, osteoarthritis) can be a significant clinical challenge. Prospective clinical trials demonstrating the efficacy of NSAIDs in these cats are typically not sufficiently powered to detect adverse effects of <3% incidence; therefore, there are safety concerns with extended clinical use of these drugs.

This study aimed to detect robenacoxib-associated adverse effects with ≥1% incidence. A pooled analysis of clinical safety variables previously reported in 4 randomized, double-blinded, placebo-controlled, prospective clinical trials in cats with chronic musculoskeletal disease was performed. Data from 449 cats treated once daily with oral robenacoxib (target dose, 1 mg/kg; range, 1-2.4 mg/kg; n = 222) or placebo (n = 227) for 4 to 12 weeks were analyzed. A subset of 126 cats with chronic kidney disease (CKD; primarily International Renal Interest Society [IRIS] stage 2) were also included in the robenacoxib (n = 58) and placebo (n = 68) groups. 

Safety was evaluated through changes in clinical pathology variables (ie, hematology, serum chemistry profile, urinalysis) and adverse effects reported by pet owners and clinicians. Variables of primary interest included cats with at least one adverse effect, relative risk for adverse effects, and impact of CKD on adverse effects. Clinical pathology variables were analyzed as secondary outcomes. 

There were no significant differences in frequency of adverse effects between cats given placebo or robenacoxib. Serum creatinine concentrations were higher during robenacoxib administration compared with placebo but were not associated with clinical adverse effects. There was no significant effect of CKD or treatment/CKD interaction on adverse effects or serum creatinine. 

Clinical tolerability was good in cats with chronic musculoskeletal disease and cats with IRIS stage 2 CKD given oral robenacoxib for 4 to 12 weeks. A possible increase in serum creatinine concentration warrants monitoring. Effect of longer treatment duration (>12 weeks), impact on adverse effects of <1% incidence, potential for GI damage, and effect in cats with more advanced CKD (ie, IRIS stage 3 or 4) are unknown.

… TO YOUR PATIENTS

Key pearls to put into practice:

1

Extended clinical use of NSAIDs (eg, robenacoxib, meloxicam) in cats is generally safe,1 but patients should be monitored for hepatic, GI, and urinary tract adverse effects.

 

2

Because of the role of prostaglandins in regulating renal blood flow during conditions of hypoperfusion (eg, dehydration, hypotension), patients should be euhydrated and normovolemic during NSAID therapy.2

3

In order to maximize efficacy and minimize dose-related adverse effects in cats with chronic musculoskeletal disease, lower doses of NSAIDs as part of a multimodal approach to pain management should be considered versus higher doses as a single modality.3

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Cardalis CB October 2022

Heterobilharzia americana Infection & Schistosomiasis in Dogs

Nicole Szafranski, DVM, University of Tennessee

Richard Gerhold, DVM, MS, PhD, DACVM, University of Tennessee

Parasitology

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<em>Heterobilharzia americana</em> Infection & Schistosomiasis in Dogs

In the literature

Graham AM, Davenport A, Moshnikova VS, et al. Heterobilharzia americana infection in dogs: a retrospective study of 60 cases (2010-2019). J Vet Intern Med. 2021;35(3):1361-1367.

FROM THE PAGE …

Heterobilharzia americana is the causative agent of canine schistosomiasis. Although raccoons are the natural host, dogs can act as definitive hosts. Canine schistosomiasis has historically been diagnosed in the Gulf Coast of the United States, but recent studies report an expansion in geographic range as far as Kansas and Utah.1,2 

The free-swimming life stage (ie, cercaria) of the parasite leaves its intermediate host, an aquatic lymnaeid snail, and penetrates the skin of a raccoon or dog. From the skin, it migrates through the lungs and liver to the mesenteric veins to mate. Eggs are deposited in the host’s intestinal lumen and passed in the feces. Hematogenous dissemination of eggs causes severe granulomatous reactions in dogs. Typically, young large-breed dogs have a greater risk for exposure, but any dog that comes in contact with potentially contaminated water is at risk.

H americana generally causes granulomatous GI and hepatic disease; clinical presentation and signs can vary.3 Diagnosis can be challenging and may require submission of feces to a diagnostic veterinary parasitology laboratory. Saline fecal sedimentation and/or histopathology have been the primary diagnostic tools used to diagnosis H americana. A sensitive fecal PCR test was recently developed and can help in the earlier diagnosis of, and potential improved prognosis for, H americana infection.4

This retrospective study examined the medical records of 60 dogs from 2 veterinary referral hospitals in Texas from 2010 to 2019 to explore clinical findings, diagnostic methodology, and treatment outcomes. The most common clinical signs included diarrhea (55.8%), vomiting (46.2%), and weight loss with or without anorexia (15.4%). Laboratory abnormalities included hyperglobulinemia (42.6%), elevated liver enzymes (30%), moderate eosinophilia of >500/µL (42.3%), anemia (17.6%), and hypercalcemia (11.6%). Ultrasound images disclosed pinpoint hyperechoic foci in the intestines, liver, or mesenteric lymph nodes in 64.4% of dogs. 

Although diagnostic methods varied between patients, 81.7% of dogs were diagnosed with H americana via PCR alone. Of the remaining dogs, 6 were diagnosed via biopsy, 3 via either direct fecal smear or sedimentation, and 2 at necropsy. Treatment plans were highly individualized, but the majority included a combination treatment of praziquantel and fenbendazole, with retreatment as needed on a case-by-case basis. Survival information was available for 34 of 56 dogs that underwent treatment; 25 of the 34 dogs (73.5%) were still alive 6 months after diagnosis. Mortality rate was thus 17.6%.

… TO YOUR PATIENTS

Key pearls to put into practice:

1

H americana infection should be considered in dogs with chronic GI signs and a history of exposure to outdoor water sources.

 

2

Ultrasonography and fecal PCR should be considered as standard testing methods to aid in earlier diagnosis of H americana and potentially provide better treatment outcomes.

 

3

Increased awareness of H americana is warranted because of its geographic spread.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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WVC Conference CB October 2022

Findings & Prognosis for Refeeding Syndrome in Cats

Janine M. Calabro, DVM, DACVECC, Friendship Hospital for Animals, Washington, D.C.

Emergency Medicine & Critical Care

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Findings & Prognosis for Refeeding Syndrome in Cats

In the literature

Cook S, Whitby E, Elias N, Hall G, Chan DL. Retrospective evaluation of refeeding syndrome in cats: 11 cases (2013-2019). J Feline Med Surg. 2021;23(10):883-891.

FROM THE PAGE...

Refeeding syndrome in cats is a complex condition characterized by multiple metabolic derangements (including hypophosphatemia, hypokalemia, and hypomagnesemia) that develops after reintroduction of nutrition following prolonged starvation or malnourishment.

This study used medical records from 4 referral hospitals to describe clinicopathologic findings, management, and outcome in 11 cats that developed refeeding syndrome after having been missing. Inclusion criteria included presence of a refeeding syndrome risk factor (eg, emaciation or severe weight loss following presumed starvation); hypophosphatemia or a maximum drop in phosphorous of ≥30% after refeeding; hypokalemia, hypoglycemia, and/or hyperglycemia; and treatment based on clinical diagnosis of refeeding syndrome. Data on clinicopathologic findings, blood product administration, nutritional plans, evidence of organ dysfunction, length of hospitalization, and outcomes were collected.

Cats had been missing for a median of 6 weeks (range, 3-104 weeks; n = 11), and mean percentage weight loss was 46% ± 7% (n = 8). Hypokalemia, hypoglycemia, hyperglycemia, and elevations in bilirubin and ALT were common. Organ and cardiovascular dysfunctions were documented in all cats; hypotension was noted in 6 cats. GI dysfunction, most often inappetence after initial feeding, developed in all cats. New or progressive neurologic deficits after refeeding were seen in 8 cats. All cats developed anemia, with 7 cats requiring transfusion therapy, and 6 cats developed acute kidney injury (AKI). All cats ate initially after presentation, and 4 cats ate voluntarily throughout hospitalization.

Eight cats survived to discharge; 1 cat died, and 2 cats were euthanized. Surviving cats were hospitalized for a mean of 14 ± 4 days. Maximum bilirubin concentration was significantly higher in nonsurvivors, and AKI was significantly associated with nonsurvival. ALT concentration and magnitude of decrease in phosphorous were not associated with outcome.

...TO THE PATIENT

Key pearls to put into practice:

1

Refeeding syndrome is an uncommon clinical condition that may develop following realimentation after prolonged starvation or malnutrition. A variety of clinicopathologic changes are possible, but  hypophosphatemia, hypokalemia, and altered glucose homeostasis are most common in cats.

2

Cardiovascular, neurologic, and GI dysfunction may be common in cats with refeeding syndrome, and patients may develop anemia that requires transfusion therapy. Increased bilirubin and AKI appear to be associated with nonsurvival.

3

Good prognosis is possible, but prolonged and intensive care may be required.

Suggested Reading & Author Information

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Royal Canin CB October 2022

Malassezia spp Treatment Outcome

William Oldenhoff, DVM, DACVD, ACCESS Specialty Animal Hospital, San Fernando Valley, California

Dermatology

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<em>Malassezia</em> spp Treatment Outcome

In the Literature

Boone JM, Bond R, Loeffler A, Ferguson EA, Hendricks A. Malassezia otitis unresponsive to primary care: outcome in 59 dogs. J Vet Dermatol. 2021;32(5):441-e119.

FROM THE PAGE…

Recurrent yeast otitis externa is common in dogs and can be difficult to treat. These patients are thus often referred to a veterinary dermatologist. 

This retrospective case series looked at treatment outcomes of 59 dogs with recurrent or persistent Malassezia pachydermatis otitis externa that were referred to dermatology specialists. Chronic M pachydermatis otitis externa was successfully treated in 91% of affected ears. Most of these cases (87%) received a single anesthetized ear flush, after which topical antifungal ear drops were applied. Median time to resolution was 27 days. Duration of otitis externa was not found to affect the length of time required for resolution. 

To reverse pathologic changes to the ear canal and to facilitate treatment, 46 of the dogs were given oral corticosteroids (ie, prednisolone or methylprednisolone) prior to ear flushing. Oral antifungals did not affect odds of treatment success. It was estimated that at least 50% of the study patients showed evidence of allergy, although the authors noted this is likely an underestimation because use of corticosteroids may have masked clinical signs.

…TO YOUR PATIENTS

Key pearls to put into practice:

1

Yeast otitis is common and can be difficult to treat, but successful management is possible. Oral corticosteroids are important in most cases to reverse chronic changes secondary to chronic otitis. Oral antifungals are not necessary for treatment of yeast otitis; focus should instead be on corticosteroids to open the ear canal, an anesthetized flushing procedure of the external canal, and topical antifungal ear drops.

2

Yeast is a normal commensal organism of the ear canal, and overgrowth occurs secondary to primary disease. At least 50% of the dogs in this study were likely allergic. Although allergy (either food or environmental) is one of the most common causes of recurrent otitis, other disorders (eg, endocrinopathies, keratinization disorders) should also be considered. Successful management of recurrent otitis depends on identifying and treating the primary cause.

3

Anesthetized ear flush procedures are underused for treatment of chronic otitis externa. Flushing with sterile saline can remove thick debris, which can be an impediment to successful management. Although special irrigation equipment can be helpful, an ear flush can also be performed with sterile saline and gentle flushing using a large syringe and red rubber catheter.

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Nocita CB October 2022
Nocita CB October 2022
Nocita CB October 2022

Ophthalmic Screening for Systemic Hypertension in Cats

Ronald Spatola, DVM, MS, DACVO, The Animal Eye Institute, Cincinnati, Ohio

Ophthalmology

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Ophthalmic Screening for Systemic Hypertension in Cats

In the literature

Moretto L, Lavaud A, Suter A, Günther C, Pot S, Glaus T. Reliability of detecting fundus abnormalities associated with systemic hypertension in cats assessed by veterinarians with and without ophthalmology specialty training. J Feline Med Surg. 2021;23(10):921-927.

FROM THE PAGE...

Fundoscopy is essential in screening for ocular and systemic disease in cats and allows quick, noninvasive, direct visualization of neurologic and vascular tissue. Detection of fundic lesions can lead to early recognition of disease processes, helping direct further diagnostics and treatment.

This study compared the ability of a recent veterinary graduate and a board-certified veterinary ophthalmologist (or veterinary ophthalmology resident under direct supervision) to detect retinal lesions associated with systemic hypertension (SHT) in cats. Cats were client-owned and had suspected hypertensive target organ damage (TOD) or were otherwise at risk for SHT with initial elevated systolic blood pressure (BP). Cats with TOD and BP >160 mm Hg were considered truly hypertensive, and cats without TOD with serial BP measurements <160 mm Hg were controls. The recent graduate used indirect ophthalmoscopy with a 28-diopter condensing lens; the ophthalmologist used 28-, 20-, and/or 15-diopter lenses.

Of 33 cats, 27 were confirmed to have SHT based on TOD or subsequent BP measurements. Veterinary ophthalmologists were able to detect fundic lesions in 24 cats with SHT. The recent graduate was able to detect fundic lesions in 19 of the 24 cats (72% sensitivity), as well as fundic lesions (including hemorrhage and retinal detachment) in every cat presented for blindness, but subtle lesions (eg, focal retinal edema, petechial retinal hemorrhages, peripheral retinal vascular tortuosity) were more likely to be missed. A training effect was observed; the recent graduate was less likely to miss lesions as the study progressed.  

Results suggest nonspecialty-trained clinicians can detect routine fundic lesions in cats with SHT, especially with practice; however, detection of subtle lesions may require evaluation by a clinician trained in veterinary ophthalmology.

...TO YOUR PATIENTS

Key pearls to put into practice:

1

Indirect ophthalmoscopy can help screen for ocular and systemic disease, especially in patients with systemic hypertension and/or vision loss.

2

Regularly practicing fundoscopy can help sharpen skills and lead to more accurate detection of fundic lesions. A Finoff transilluminator and condensing lens (28 diopter or 2.2 pan retinal) is sufficient for clinicians without specialty ophthalmology training.

3

Patients with suspected systemic and/or ocular disease with no evidence of ocular lesions detected by the primary clinician should be referred to a veterinary ophthalmologist to identify subtle lesions and avoid a delay in diagnosis and treatment.

Suggested Reading & Author Information

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

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Nestle CB October 2022
Nestle CB October 2022
Nestle CB October 2022
Nestle CB October 2022

Research Note: Point-of-Care Test for Mushroom-Related Amatoxicosis in Dogs

Emergency Medicine & Critical Care

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Amatoxins are the causative agent of mushroom hepatotoxicosis and can affect multiple organ systems but primarily target the liver. Initial signs (eg, vomiting, lethargy, fever, hypoglycemia) are not pathognomonic and can be mistaken for other conditions (eg, anaphylaxis, sepsis, other causes of acute hepatic failure), especially when ingestion is not suspected or witnessed. Presumptive diagnosis is generally based on patient history, clinical signs, and changes in the serum chemistry profile; however, an inexpensive point-of-care lateral flow immunoassay for amanitin detection in canine urine is commercially available. 

This case study was the first to report diagnosis of amatoxicosis via point-of-care lateral flow immunoassay in a dog prior to treatment. The patient made a full recovery and was discharged 4 days after hospitalization. Early diagnosis can help guide treatment decisions; additional studies are needed to determine whether survival rates improve with early detection.

Source & References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

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Pedal Papilloma in Dogs

Charlie Pye, DVM, DVSc, DACVD, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada

Dermatology

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Pedal Papilloma in Dogs

In the literature

Gould AP, Coyner KS, Trimmer AM, Tater K, Rishniw M. Canine pedal papilloma identification and management: a retrospective series of 44 cases. Vet Dermatol. 2021;32(5):509-e141.

FROM THE PAGE …

Papillomavirus infections in dogs have been associated with oral papilloma, venereal papilloma, exophytic cutaneous papilloma, cutaneous inverted papilloma, footpad papilloma, pigmented viral plaque, and development of squamous cell carcinoma.1 Although studies on pedal papilloma have been infrequent, this syndrome appears to be common. 

The goal of this study was to report patient signalment, history, treatment, and outcome of biopsy-confirmed pedal papillomatosis cases in North America based on 44 cases submitted by members of an online veterinary community. Median age of dogs was 4 years; 27.3% were <1 year of age. Thirty breeds were represented, with pit bulls, golden retrievers, and Labrador retrievers and their crossbreeds accounting for 36% of cases. The most common clinical signs associated with pedal papilloma were paw licking/chewing and lameness.   Only one paw was affected in 35 dogs; of these, 26 were affected on a thoracic paw. Papillomavirus infection may be associated with trauma,2 possibly leading to thoracic paws being affected more often, as thoracic paws bear more weight compared with pelvic paws and have more contact time with the ground, increasing susceptibility to trauma.3,4 

Most dogs (n = 28) had a single papilloma, 2 dogs had 2 papillomas, 5 dogs had 3 to 5 papillomas, and 7 dogs had >5 papillomas. Papillomas typically appeared on haired skin of the paw, but 10 dogs developed papillomas on the paw pads, and 2 dogs developed papillomas on the claw beds. The ventral interdigital region and the underside of a digit were the most common focal locations.

Papillomas resolved in 34 cases (15 with no treatment beyond biopsy collection, 19 with medical therapy), and 25 cases resolved within 3 weeks after biopsy. Recurrence was reported in 5 cases, with recurrence at the same location in 3 cases, at both the same location and distant sites in another case, and at a different site in another case. Same-site recurrence developed within 4 months after excision. 

Nearly half of all dogs received no treatment after confirmatory biopsy was collected, and the lesions in most dogs resolved spontaneously. The authors noted it was challenging to determine the efficacy of antiviral treatment, as many papillomas resolved within 3 weeks.

… TO YOUR PATIENTS

Key pearls to put into practice:

1

Papillomas can resolve quickly with or without medical therapy; however, risk for same-site recurrence should be considered.

 

2

Paws should be examined thoroughly for masses in patients presented for lameness and/or paw licking/chewing.

 

3

This study did not support a strong association between immunosuppressive medications or comorbidities and development of pedal papillomatosis.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Plumb's Pro CB October 2022

Foreign Body Ingestion & Behavior Disorders in Dogs

Leslie Sinn, CPDT-KA, DVM, DACVB, Behavior Solutions for Pets, Hamilton, Virginia

Behavior

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Foreign Body Ingestion & Behavior Disorders in Dogs

In the literature

Masson S, Guitaut N, Medam T, Béata C. Link between foreign body ingestion and behavioural disorder in dogs. J Vet Behav. 2021;45:25-32.

FROM THE PAGE ...

The influence of behavioral disorders on the occurrence of pica, foreign body ingestion, and subsequent obstruction is undetermined. Many behavioral disorders (eg, lack of impulse control, hyperactivity, obsessive compulsive disorders) have been proposed as possible causes of foreign body ingestion.

Researchers in this retrospective, owner-based study used 2 questionnaires: the 4A scale (owner assessments of behavior along 4 axes [auto-control, attachment, anxiety, aggressiveness]) and an attention-deficit/hyperactivity disorder rating scale (owner assessment of hyperactivity–impulsivity and inattention levels).1,2 Both questionnaires were used to quantify the extent of behavior concerns in 42 affected dogs and their pair-matched controls.

Affected dogs were categorized as senior dogs with no previous history of ingestion (current foreign body ingestion was due to suspected GI problems or underlying pain), older dogs that occasionally ingested foreign bodies, or younger dogs that regularly shredded and ingested nonedible objects. Results suggested foreign body ingestion is primarily driven by behavior abnormalities (88%) versus GI pain and discomfort (12%). Results also suggested that shredding objects is linked to hyperactivity–impulsivity disorder; however, absence of this behavior in patients with foreign body ingestion suggests anxiety or attachment disorder.

… TO YOUR PATIENTS

Key pearls to put into practice:

1

Regular object shredding by dogs should raise concern and prompt further behavioral evaluation.

 

2

Potential behavior causes should be investigated in any dog that exhibits pica.

 

3

GI disorders and pain were not found to be the primary cause of foreign body ingestion in this study, but other studies have found a significant link between pain and abnormal behavior, including foreign body ingestion.3,4 A thorough physical examination and appropriate additional diagnostics (including GI analysis, if indicated) should be pursued.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Douxo PYO CB October 2022

Significance of Subclinical Heart Murmurs in Cats

Nancy J. Laste, DVM, DACVIM (Cardiology), Bulger Veterinary Hospital, Lawrence, Massachusetts

Cardiology

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Significance of Subclinical Heart Murmurs in Cats

In the literature

Franchini A, Abbott JA, Lahmers S, Erikkson A. Clinical characteristics of cats referred for evaluation of subclinical cardiac murmurs. J Feline Med Surg. 2021;23(8):708-714.

FROM THE PAGE …

Subclinical cardiac murmurs have a reported prevalence of 15.5% to 34% in cats.1,2 Benign heart murmurs (ie, not associated with structural heart disease on echocardiography) are relatively common.1,2 Echocardiography remains the gold standard to evaluate for cardiac disease.

In this study, medical records of 163 apparently healthy cats with subclinical heart murmurs were evaluated for prevalence of heart disease and to define clinical characteristics that can help identify patients with heart disease. Most cats were domestic shorthair or domestic longhair (87.7%), and the remaining cats were purebred (eg, Maine coon, Siamese); 62.6% of cats were male, and body weight was significantly higher in male cats. 

Cardiac disease was identified via echocardiogram in 66.3% of cats. Those with a hypertrophic cardiomyopathy (HCM) phenotype (ie, either HCM or left ventricular hypertrophy secondary to systemic hypertension or hyperthyroidism) accounted for 88.9% of heart disease cases. Of the 55 cats without identified heart disease, 30 (54.4%) had dynamic left ventricular outflow tract obstruction, dynamic right ventricular outflow tract obstruction, or concurrent left and right ventricular outflow tract obstruction. Murmurs were classified as innocent in the remaining cats. Left atrial enlargement was generally mild and identified in 41 cats (25.1%), including 3 without identified heart disease.

HCM is the most frequently identified type of heart disease in cats with subclinical heart murmurs.1-3 HCM prevalence in this study was higher (88.9%) than in similar studies,1-3 possibly because this study group was a referral population, and cats with more intense murmurs may be more likely to be referred. 

… TO YOUR PATIENTS

Key pearls to put into practice:

1

Subclinical heart murmurs are common in cats, and most affected cats referred for evaluation of a heart murmur have mild disease with minimal left atrial enlargement and are therefore at relatively low risk for complications (eg, congestive heart failure, aortic thromboembolism). 

2

HCM is diagnosed in a significant percentage (>80%) of cats with subclinical heart murmurs.

 

3

Cats that are male, weigh more, and have a murmur of III/VI or louder may be more likely to have heart disease.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Epicur Oncology Webinars CB October 2022

Research Note: Splenectomy for Immune-Mediated Hematologic Disorders in Dogs

Internal Medicine

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Immune-mediated hemolytic anemia (IMHA) and immune-mediated thrombocytopenia (ITP) are common in dogs; concurrent IMHA and severe thrombocytopenia (CIST) is also possible. Mainstay therapy for IMHA and ITP consists of immunosuppressive doses of glucocorticoids with or without adjunctive immunomodulatory therapy. Splenectomy may be an option in patients with a poor or refractory response to medical management or those unable to continue therapy (eg, due to cost, adverse effects), but only small case series have documented this treatment. 

This study sought to describe clinical outcomes of dogs with IMHA, ITP, or CIST that underwent splenectomy. Improvement was seen most consistently in dogs with ITP (6 out of 7 dogs); 4 out of 7 dogs with IMHA showed improvement, and only 1 out of 3 dogs with CIST had a complete response. Splenectomy was considered successful and well tolerated in most dogs with ITP; however, clinical benefit in patients with IMHA or CIST could not be determined.

Source & References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

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Podcast CB October 2022

Research Note: Sequential Organ Failure Assessment Scoring in Septic Dogs

Emergency Medicine & Critical Care

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Sepsis (ie, systemic inflammatory response syndrome with an infectious nidus) is associated with high morbidity and mortality. Rapid diagnosis may enable early intervention and improved outcome; however, diagnosis is difficult because there is currently no single reliable test, clinical finding, or scoring system for sepsis. The quick sequential-related organ failure assessment (qSOFA) scoring system was developed to have greater specificity than systemic inflammatory response syndrome criteria for predicting mortality and recognizing organ dysfunction in humans with suspected sepsis. 

This study used different respiratory rate cutoffs to evaluate the prognostic usefulness of qSOFA scoring in dogs with severe sepsis and septic shock, as well as the clinical value of qSOFA scoring for predicting severe sepsis and septic shock in critically ill dogs presented to an emergency clinic. qSOFA scoring at all respiratory rate cutoffs revealed poor mortality prediction and low sensitivity for detection of severe sepsis and septic shock and should thus not be used alone when screening for sepsis.

Source & References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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AHS CB October 2022

Foreign Body Obstruction in Dogs: Comparing Outcomes of Enterotomy with Intestinal Resection & Anastomosis

Lisa Corti, DVM, DACVS, CCRP, North Shore Veterinary Surgery, Andover, Massachusetts, North Shore Community College, Danvers, Massachusetts

Emergency Medicine & Critical Care

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Foreign Body Obstruction in Dogs: Comparing Outcomes of Enterotomy with Intestinal Resection & Anastomosis

In the literature

Lopez DJ, Holm SA, Korten B, Baum JI, Flanders JA, Sumner JP. Comparison of patient outcomes following enterotomy versus intestinal resection and anastomosis for treatment of intestinal foreign bodies in dogs. J Am Vet Med Assoc. 2021;258(12):1378-1385.

FROM THE PAGE …

Intestinal foreign body obstructions can be removed either through enterotomy or intestinal resection (IRA) and anastomosis of a bowel segment, depending on the viability of the associated intestine. Risk factors for postoperative intestinal dehiscence (eg, septic peritonitis, low serum albumin levels, intraoperative hypotension) are well established,1-4 but published dehiscence rates for enterotomy and IRA vary.2-6 

This study sought to clarify the risk for dehiscence in dogs undergoing IRA compared with enterotomy and evaluated use of early enteral nutrition administered via nasogastric tube to improve clinical outcomes. Nasogastric tubes were placed intraoperatively at the surgeon’s or resident’s discretion and were used to administer a commercial liquid diet during the first 24 hours postoperatively. 

Retrospective analysis of 227 foreign bodies removed from the small intestine of 211 dogs at a veterinary teaching hospital found a dehiscence rate of 3.8% with enterotomy and 18.2% with IRA. The odds of dehiscence after IRA were 6.09 times greater than with enterotomy; however, multivariate analysis of factors that may influence intestinal healing revealed that only older patients and those with an American Society of Anesthesiologists (ASA) score >3 were significantly associated with increased risk for intestinal dehiscence, regardless of procedure. The odds of dehiscence increased by 1.24 for each year of age increase. 

Benefits of early enteral nutrition could not be accurately assessed, as the hospital switched to routine use of nasogastric tubes for foreign body surgery, but data revealed that longer periods until voluntary food intake significantly increased the odds for intestinal dehiscence.

Limitations of the study included retrospective data collection, nonrandomization of nasogastric tube placement, and the inherent inability to randomize the procedure used for foreign body removal. Suture types, sizes, and patterns were not included in statistical analyses and may have affected reported outcomes because they influence intestinal healing.1,7 Analgesia protocols (eg, whether opioids were administered during the postoperative period) were not studied. Pure mu-agonist opioids decrease gastric emptying time, diminish propulsive intestinal motility, and cause nausea and vomiting.8,9 Further study is needed to evaluate whether postoperative opioid use delays time to first voluntary food intake and subsequently influences intestinal dehiscence rates.

… TO YOUR PATIENTS

Key pearls to put into practice:

1

IRA for foreign body removal has a significantly higher rate of postoperative dehiscence than enterotomy.

 

2

Older patient age and an ASA score >3 may increase the risk for intestinal dehiscence, regardless of procedure used, and may be predictive of a patient's ability to heal.6,10

 

3

Early voluntary food intake after foreign body surgery may decrease the risk for intestinal dehiscence. Methods to improve appetite (eg, preanesthetic administration of maropitant, reduced reliance on opioids due to use of locoregional anesthesia or lidocaine and ketamine CRIs, postoperative administration of a ghrelin agonist) warrant consideration.9,11-13

4

Results of this study should guide understanding of potential postoperative sequelae, not dictate procedure selection. If poor intestinal viability warrants IRA, or if there are other risk factors (eg, low serum albumin, intraoperative hypotension, old age, higher ASA score), the owner may need to be informed about the need for aggressive and prolonged 24-hour care and monitoring.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Algorithm CB October 2022

Drugs Used for Emesis Induction in Dogs

Jack Lee, DVM, University of Tennessee

Adesola Odunayo, DVM, MS, DACVECC, University of Tennessee

Pharmacology & Medications

|Peer Reviewed

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Drugs Used for Emesis Induction in Dogs

Ropinirole

Ropinirole is an FDA-approved selective D2 agonist that acts on the CRTZ to induce emesis in dogs.

Formulation

  • Ophthalmic solution (30 mg/mL) in single-use droppers

Dosage

  • 3.75 mg/m2 ophthalmic (see Table for number of drops)10 

Key Points

  • 95% efficacy in healthy dogs in one study11
  • A second dose can be administered if vomiting does not occur within 20 minutes.10
  • Should not be given to patients with pre-existing ocular irritation, ulceration, or injury10 
  • Most commonly reported adverse effects include tachycardia, lethargy, and hypotension. Mildly to moderately injected gums, elevated third eyelid(s), and conjunctival discharge were transiently noted.11,12 
  • Can be specifically antagonized by metoclopramide in cases of protracted emesis11 
  • Not expected to work in cats due to the low number of dopamine receptors in the CRTZ13
  • Not labeled for use in cats

table

ROPINIROLE OPHTHALMIC SOLUTION MANUFACTURER RECOMMENDATIONS10

Weight Number of drops
4-11.1 lb (1.8-5 kg) 1
11.2-22.1 lb (5.1-10 kg) 2
22.2-44.1 lb (10.1-20 kg) 3
44.2-77.2 lb (20.1-35 kg) 4
77.3-132.3 lb (35.1-60 kg) 6
132.4-220.5 lb (60.1-100 kg) 8

 

*Table adapted from package insert.52

Apomorphine

Apomorphine induces emesis via nonselective dopamine receptor agonism in the CRTZ. Cross-reactivity with opioids, 5-hydroxytryptamine, and alpha-adrenergic receptors can contribute to adverse effects (eg, sedation).14 Apomorphine is generally the emetic of choice in dogs because of its rapid onset and ability to reverse action; however, this drug is not recommended in cats due to lack of efficacy and dopamine-mediated hyperexcitability.15,16 Use of apomorphine as an emetic is extra-label in dogs.17 

Formulation

  • Injectable and ocular formulations available in various concentrations 
  • Tablets available in some areas 
  • Usually obtained through compounding pharmacies17 

Dosage

  • 0.03 mg/kg IV, 0.04 mg/kg IM, or 0.01-0.04 mg/kg SC17
  • Subconjunctival: crushed 6.25 mg tablet dissolved in sterile isotonic saline and applied to the conjunctiva
  • Gingival: 6.25 mg tablet dissolved onto the gingival mucosa18

Key Points

  • Appears to be highly effective in dogs, with successful emesis reported in 80% to 97% of cases12,18,19 
  • SC or IV administration may be more effective than IM.20 
    • In a study, SC administration was as effective as IV administration in inducing emesis12,17,19; however, median time to onset of emesis was 13.5 minutes and 2 minutes for SC and IV administration, respectively.
    • IV administration has a faster onset than IM or SC; therefore, the IV route should be used following ingestion of toxicants associated with rapid GI absorption. 
  • Depending on regional availability, the injectable form may need to be compounded or made by aseptically dissolving a tablet and administering through a filter.21,22
    • Apomorphine solutions are not stable and should be freshly made before each administration.  
  • Gingival administration (ie, massaging one tablet onto the gingiva for 3-5 seconds until fully dissolved) can be highly effective.18
    • Not effective when administered orally due to heavy first-pass metabolism18 
  • Should be freshly made before applying to the conjunctiva; diluting the pill with sterile saline minimizes ocular irritation, and the eye should be copiously flushed once vomiting occurs.17 
  • Ocular inserts (2 mg/insert) can also be used successfully (83.5%).23
  • Administration can be repeated if needed, but adverse effects (eg, sedation) are dose dependent.19
    • Other adverse effects include excessive vomiting, tachycardia, and CNS depression, which may be exacerbated in patients with the multidrug sensitivity gene (MDR1 gene, also known as ABCB1 gene).24,25 
    • Ocular irritation may occur with conjunctival administration.12,17,26 
  • Naloxone reverses sedation without affecting nausea.17

Hydrogen Peroxide

Hydrogen peroxide induces emesis through direct stimulation of peripheral afferents in the esophagus and stomach and is typically administered by the pet owner or when other emetics are unavailable. This drug should not be given to cats due to the high risk for adverse effects (including potentially fatal necroulcerative hemorrhagic gastritis) and inconsistent emetic effects.27 Use of hydrogen peroxide as an emetic is extra-label in dogs. 

Formulation 

  • 3% solution
  • Higher concentrations (eg, 30% solutions) should not be used. 

Dosage

  • 1-2.2 mL/kg PO (maximum, 45-50 mL/dog)26,28

Key Points

  • Efficacy of up to 90% was reported in one study.26
  • An additional dose may be administered if emesis is not successful after 10 to 15 minutes.28
  • Adverse effects include persistent GI signs and lethargy. Significant esophageal and gastric lesions, including necrosis and air embolization, can occur even in healthy dogs.26,29
  • Risk for adverse effects should be weighed against the danger of the toxicant prior to recommending at-home emesis induction.

Tranexamic Acid (TXA)

Tranexamic acid (TXA) is a plasminogen lysine analogue primarily studied for its antifibrinolytic effects. TXA is thought to induce vomiting via NK-1 receptor agonism and has been shown to bind within the emetic center and CRTZ.30 Use of TXA as an emetic is extra-label in dogs and is rarely used for this purpose. 

Formulation

  • Injectable (100 mg/mL)

Dosage

  • 50 mg/kg IV once (repeat administration of 20-50 mg/kg may be given 1-2 times if needed)31-33

Key Points

  • Efficacy of 94% in one study33; generally causes 1 to 2 episodes of vomiting within minutes
  • Adverse effects are rare but may include seizures and hemostatic disorders, including decreased fibrinolysis.33,34
  • Availability may vary significantly by region, and use may be cost prohibitive.

Poll

How frequently do you need to induce emesis in dogs in your practice?

Not Recommended

The following are not recommended for emesis induction in dogs.

  • Salt
    • Risk for hypernatremia and sodium toxicosis49
  • Syrup of ipecac 
    • Risk for cardiotoxicosis49
  • Sodium carbonate or other irritants 
    • Potential for severe mucosal injury and lower efficacy50,51

Many drugs with species-specific indications and adverse effects are available for inducing emesis in dogs and cats. Prompt emesis induction can reduce life-threatening adverse effects of toxicants or bowel obstruction associated with ingestion of foreign material.

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

Drugs Used for Emesis Induction in Cats

Jack Lee, DVM, University of Tennessee

Adesola Odunayo, DVM, MS, DACVECC, University of Tennessee

Pharmacology & Medications

|Peer Reviewed

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Drugs Used for Emesis Induction in Cats

Dexmedetomidine

Dexmedetomidine is an alpha-2–adrenergic agonist that acts on the CRTZ to induce emesis in cats.16 This drug is generally considered the emetic agent of choice in cats due to high concentration of alpha-2–adrenergic receptors in the CNS; in dogs, however, alpha-2–adrenergic agonists are unlikely to induce emesis. Use of dexmedetomidine as an emetic is extra-label.

Formulation

  • Injectable (100 or 500 µg/mL)

Dosage

  • 7-10 µg/kg IM (up to 18 µg/kg has been reported)35
  • 3.5 µg/kg IV35

Key Points

  • Efficacy is reported as 58% to 81%.4,16
  • Evidence in cats supports superior efficacy compared with xylazine.4
  • Sedative adverse effects can be reversed with atipamezole.35
  • Other common adverse effects include peripheral vasoconstriction, hypertension, arrhythmias, and reflex bradycardia.35 
  • Caution should be used in cats with cardiac disease or hemodynamic instability. 
  • Administration of butorphanol may reduce the emetic effect.36
  • One study evaluating application of oral detomidine transmucosal gel in cats demonstrated that 100% of healthy cats vomited after administration,37 making this route of administration a possible alternative to injectable dexmedetomidine for emesis induction. 
    • Avoiding needles may reduce anxiety related to visiting the clinic and promote stress-free handling in cats.

Related Article

Dexmedetomidine & Atipamezole

Xylazine

Xylazine is an alpha-2–adrenergic agonist that acts on the CRTZ to induce emesis in cats.38 Although xylazine has historically been the agent of choice in cats, dexmedetomidine is currently more readily available and preferred. Use of xylazine as an emetic is extra-label.

Formulation

  • Injectable (20 or 100 mg/mL)

Dosage

  • 0.44 mg/kg IM39
  • 1.1 mg/kg IM or SC39

Key Points

  • Efficacy is reported as 51% to 60%.4,16,40
  • Adverse effects include hypertension, hypotension, bradycardia, CNS depression, and sedation.39,41 
  • Alternative drugs should be considered in patients with cardiac disease or hemodynamic instability.
  • May be reversed with yohimbine or tolazoline39   

Brimonidine

Brimonidine is an ophthalmic alpha-2–adrenergic agonist primarily used in the treatment of elevated intraocular pressure. Use of brimonidine as an emetic is extra-label.  

Formulation

  • Ophthalmic (0.1%, 0.15%, or 0.2%)

Dosage

  • 1 drop in either eye42

Key Points

  • Efficacy is reported as 80% to 100% in small populations of cats.37,43
  • Adverse effects include hypotension, hypertension, bradycardia, and CNS depression.42 
  • Alternative drugs should be considered in patients with cardiac disease or hemodynamic instability.

Hydromorphone

Hydromorphone is a pure mu-opioid agonist that induces emesis through stimulation of the CRTZ. Although the emetic adverse effects of pure mu opioids have been well documented in dogs and cats,44,45 use as an emetic in dogs is not reported. Use of hydromorphone as an emetic is extra-label.   

Formulation

  • Injectable (1, 2, or 4 mg/mL)

Dosage

  • 0.1 mg/kg SC46-48

Key Points

  • Efficacy is reported as ≈75% in one study.48
  • Sedation effect may be reduced in cats compared with dexmedetomidine.48
  • Adverse effects may include sedation and hyperthermia.46
  • Sedative effects can be reversed with naloxone if needed; it is uncertain whether naloxone has an effect on the emetic actions of hydromorphone.46

Poll

What is your go-to drug for emesis induction in cats?

The following are not recommended for emesis induction in cats.

  • Salt
    • Risk for hypernatremia and sodium toxicosis49
  • Syrup of ipecac 
    • Risk for cardiotoxicosis49
  • Sodium carbonate or other irritants 
    • Potential for severe mucosal injury and lower efficacy50,51

Many drugs with species-specific indications and adverse effects are available for inducing emesis in dogs and cats. Prompt emesis induction can reduce life-threatening adverse effects of toxicants or bowel obstruction associated with ingestion of foreign material.

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Career Center CB October 2022

Intermittent Back Pain in a Young Dog

Heidi L. Barnes Heller, DVM, DACVIM (Neurology), Barnes Veterinary Specialty Services, Madison, Wisconsin

Neurology

|Peer Reviewed

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Intermittent Back Pain in a Young Dog

Chuck, a 2-year-old, 71-lb (32.3-kg) neutered male crossbreed dog, is presented for a one-year history of intermittent back pain.

History

Chuck was adopted in Canada and brought to the United States at ≈10 months of age. He has no known history of trauma. Another spayed dog also lives in the household. 

The owner reports that spinal pain appears intermittent, worsens in cold weather, and occasionally results in vocalization when Chuck’s dorsal lumbar and pelvic regions are touched. Vaccinations, heartworm/flea/tick prevention, and fecal analysis are current.

Examination

On physical examination, rectal temperature is 104.5°F (40.3°C), heart rate (100 bpm) is normal, and Chuck is panting. The remainder of the physical examination is normal.  

On neurologic examination, Chuck is bright, alert, and responsive. He demonstrates a normal menace response, pupillary light reflex (both eyes), palpebral reflex (both eyes), physiologic nystagmus (with no evidence of pathologic nystagmus), facial symmetry, sensory testing to nares and ears, and tongue tone and motor. Jaw range of motion is unchanged, and no signs of strabismus or head tilt are noted. Cranial nerve examination is normal. 

Chuck is ambulatory with a mildly stilted gait in the pelvic limbs. He is slow to lie down but appears normal when returning to standing. Normal withdrawal reflexes (all limbs), patellar reflexes (pelvic limbs), perineal reflex, and cutaneous trunci reflex (bilateral) are present. Paw replacement testing results are normal in all limbs. Hopping test is not performed due to patient size and apparent pain. 

Pain is noted on direct palpation of the lumbar and lumbosacral spine (Figures 1-3). No evidence of pain is noted on thoracic or cervical spinal palpation, and cervical range of motion is normal.

How would you diagnose and treat this patient?

Treatment & Outcome

Spinal radiography was performed, and lysis at the L7 and S1 endplates was identified (Figures 4 and 5). 

Bacterial blood culture and urine culture results were negative. Brucella canis 2-mercaptoethanol rapid slide agglutination test result was positive. Agar-gel immunodiffusion and tube agglutination tests were also positive, confirming diagnosis of B canis discospondylitis. 

Doxycycline (25 mg/kg PO every 24 hours1), rifampin (5 mg/kg PO every 12 hours), and carprofen (2.2 mg/kg PO every 12 hours) were administered. Clinical signs improved rapidly in the first 30 days of treatment; however, long-term treatment and monitoring were expected. It is common for dogs to remain positive on serologic testing, and lifelong quarantine is often required to control spread of disease. The other dog in the household also tested positive for B canis, and both dogs were placed in quarantine. The State Veterinarian was contacted for quarantine protocols and additional monitoring recommendations.

B canis infection is a reportable zoonotic disease in the United States. Transmission to humans is rare but possible. Appropriate personal protection equipment (eg, goggles or face shield, gloves, thorough handwashing) is recommended when handling aborted fetuses, urine, or blood from patients with B canis infection. Transmission to other animals can occur via mucous membrane (eg, conjunctiva of the eye, vagina, oral cavity) contact.

References

Related Article

Brucella canis in Dogs from South Dakota Reservations

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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Solensia CB October 2022
Solensia CB October 2022

Differential Diagnosis: Elevated ALP

Marie Chartier, DVM, DACVIM (Internal Medicine), VCA Roberts Animal Hospital, Hanover, Massachusetts

Internal Medicine

|Peer Reviewed

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Differential Diagnosis: Elevated ALP

Following are differential diagnoses for patients presented with elevated ALP.

  • Cholestasis (intrahepatic or posthepatic)
    • Hepatic lipidosis (cats)
    • Diabetes mellitus
    • Hyperadrenocorticism
    • Neoplasia of liver or biliary tree 
    • Infectious (eg, ascending intestinal bacteria, leptospirosis, histoplasmosis, toxoplasmosis) or inflammatory (eg, idiopathic, copper storage) hepatitis 
    • Cholecystitis or cholangitis 
    • Triaditis (ie, concurrent pancreatitis, cholangiohepatitis, and inflammatory bowel disease [cats])
    • Gallbladder mucocele 
    • Pancreatitis
    • Portosystemic shunt
    • Portal vein hypoplasia
    • Toxicity (eg, tetracyclines, NSAIDs) 
    • Nodular hyperplasia
    • Hepatic fibrosis 
    • Proximal duodenal obstruction (eg, mass or foreign body causing secondary bile duct obstruction) 
    • Reactive hepatopathy (eg, enteritis, chronic enteropathy) 
  • Induction by drugs or hormones (independent from toxicity) 
    • Phenobarbital
    • Glucocorticoids (dogs) 
    • Hyperthyroidism
    • Hypothyroidism (usually mild elevation, if any) 
  • Other
    • Increased osteoblastic activity (eg, osteosarcoma, hyperparathyroidism, bone fracture or damage, hyperthyroidism)
    • Normal bone growth (young dogs) 
    • Breed-specific conditions (eg, high ALP in Scottish terrier, benign familial hyperphosphatemia in Siberian husky) 

Suggested Reading

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Digital Edition may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

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ProZinc CB October 2022
ProZinc CB October 2022

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