On visual examination, Nonose was bright and alert, with severe respiratory stertor and subjectively increased inspiratory effort. No open-mouth breathing was noted during transport or at the clinic. He had a large lesion extending from the medial canthi across the forehead to just dorsal to the margin of the upper lips. Within these margins, no normal haired skin, nasal planum, or nares could be identified. He appeared to be visual, and mentation was deemed appropriate.

Nonose was anesthetized for further examination. The surface of the lesion was characterized by a glistening, serosanguinous, gelatinous material (Figure 3), which, when wiped with gauze, revealed exposed bone or cartilage. The full-thickness lesion extended into the mouth and through the upper left lip, creating a hole into the oral cavity (Figure 2). The proliferative nature of the lesion likely obstructed vision directly in front of the patient. Nasal passages were located after debridement but were composed of exposed nasal bone/cartilage rather than planum. All upper incisors were absent, and the gingiva surrounding all remaining teeth and the hard palate appeared affected with diffuse erythema and small amounts of the gelatinous material (Figure 4).

Due to the severity of facial tissue destruction, poor prognosis, and feral nature of the cat, euthanasia was elected. A blood sample was obtained prior to euthanasia for point-of-care FeLV/FIV testing, which was performed immediately after euthanasia and was negative. Multiple impression smears of affected tissue were obtained for cytologic examination (Figure 5).

Smears were composed of abundant round to oval-shaped, blue to pink yeast structures 3 to 12 µm in diameter. A thick, clear capsule surrounded the structures, resulting in organisms ≈5 to 20 µm in diameter. Narrow-based budding of the organisms was observed. Among the organisms were large, often vacuolated macrophages that occasionally contained one or more of the yeast structures (Figure 5).

Cryptococcal infections are seen worldwide in various species and, in the United States, are most common in California and the Pacific Northwest.¹ Basidiospores are usually found in soil or avian fecal material; infection often occurs through inhalation but can occur via direct contact of basidiospores in open wounds.^1-3 Incubation can range from a few months to years.²

Although assays to determine species were not performed in this patient, most cats in California that have cryptococcosis are infected by Cryptococcus gattii VGIII, with relatively fewer infections being due to C gattii VGII.¹ C neoformans var grubii is the most common cause of cryptococcosis in dogs and humans; in the United States, cats are rarely infected with this species.¹

In cats, cryptococcosis is generally chronic and often presents as mucosal lesions in the nasal cavity, regardless of the primary site of entry/infection of the basidiospores.^1-3 The glistening, serosanguinous gelatinous nature of the mass observed in this patient is a characteristic feature of cryptococcosis and a reflection of the presence of the polysaccharide capsule.^1,2 Meningoencephalitis, cerebral granulomas, chorioretinitis, optic neuritis, uveitis, and other lesions may also be observed.^2,3

Pathogenesis of disease and success of treatment are dependent on the type and extent of infection, host immunity, and strain of Cryptococcus spp involved.^1-3 Fungal culture is recommended, as a long course of therapy is required to resolve infection, and antifungal resistance is common.^1-3 Antifungals commonly selected for feline therapy include fluconazole (10 mg/kg PO every 12 hours) and itraconazole (5-10 mg/kg PO every 24 hours). Fluconazole is the initial antifungal agent of choice due to its good tissue penetration in the brain, eyes, and urinary tract and its relatively low cost. If the patient fails to respond to fluconazole therapy, as is often seen with C gattii infections, itraconazole may help achieve remission; however, multimodal therapy, including amphotericin B and 5-flucytosine, may be required in severe disseminated cases. Serial laboratory monitoring of liver enzymes is recommended, as liver toxicity is possible with azole therapy (see Treatment at a Glance).^1-3

Once cryptococcosis is diagnosed, a discussion should be held with the owner regarding the cost of long-term medication and laboratory monitoring, the importance of owner and patient compliance for long-term oral therapy, and the potential for disease recurrence, particularly if compliance is poor. A committed owner and a compliant patient are essential for a successful outcome.

Treatment success can be gauged by reduction in both clinical signs and serum antigen titers (at least one dilution per month of treatment); treatment should be continued until the antigen titer is 0.^1-3 Continued antigen titer monitoring after resolution of disease at 3- to 6-month intervals is recommended, as early detection of relapse can lead to shorter duration of repeat treatment (see Take-Home Messages).²

A 7-year-old spayed Labrador retriever crossbreed is presented for a 5-day history of an intermittently red, cloudy left eye. The owner states that the patient had previously been diagnosed with allergic conjunctivitis and has had intermittent flare-ups. The patient has reportedly been coughing for 3 days and, although still eating and drinking, her appetite is decreased. Her BCS is 7/9, which is consistent with previous visits. 

On general physical examination, mild mandibular lymphadenopathy, moderate dental tartar, rectal temperature of 103.8°F (39.9°C), and a tense abdomen on palpation were noted. An initial ophthalmologic examination of the left eye reveals blepharospasm; absent menace response; questionable dazzle reflex; a fixed, mid-range pupil with subtle dyscoria and no apparent direct pupillary light reflex or consensual pupillary light reflex from the left to the right eye; pronounced episcleral injection and conjunctival hyperemia; mild edema, and suspected moderate aqueous flare (Figure 1). Although a tapetal reflex is visible, the fundus in the left eye cannot be visualized by indirect or direct ophthalmoscopy. The right eye appears normal.

What are your next steps?

This case highlights the challenge of determining whether glaucoma is primary or secondary, especially if owners are financially constrained or unable to accept referral. In addition, many cases of PACG exhibit a degree of inflammation and pigment dispersion, which can further complicate the clinical picture. This case illustrates the importance of recognizing that primary glaucoma may be encountered in any breed, including crossbreed dogs. 

Dolly, a 3-year-old spayed domestic shorthair cat (Figure 1), was presented to the Dumb Friends League as a stray. Within 24 hours of intake, Dolly was noted to have hematuria. She received a full physical examination, urinalysis, and radiography of her urinary bladder and kidneys. She was found to have a cystic urolith and was taken to surgery. Cystotomy was routine, and Dolly recovered uneventfully.

Urinalysis results were consistent with sterile cystitis, and stone analysis revealed a calcium oxalate stone. Dolly was switched to Hill’s Prescription Diet c/d Multicare Feline (Figure 2), which is specially formulated to support urinary health and reduce the risk for calculi.²  Dolly had no recurrence of clinical signs on her new food and was ultimately adopted.

Although cats with urinary disease—such as Dolly—typically have longer stays in the shelter, they are still considered adoptable in most cases.³ With counseling of future owners on proper management, the Dumb Friends League has found that many of these cats go on to live a happy, healthy life.

Potential owners should be educated about stress reduction and weight control, both of which are important components of FLUTD management.^1,4 Any stressful change of routine, such as a new caretaker or reduced play time, has been shown to trigger a variety of sickness behaviors, including inappropriate urination.⁴ Adherence to routine and environmental enrichment (eg, proper hiding and perching locations) may help prevent recurrence of FLUTD.^1,4

In addition, adopters should be counseled about dietary management, which has been shown to influence FLUTD recurrence.⁵ Along with mineral concentrations and maintenance of urinary pH, antioxidant levels and omega-3 fatty acids can influence urinary health.⁵ A prospective, randomized, double-blinded study showed that Hill’s Prescription Diet c/d Multicare Feline reduced the recurrence rate of feline idiopathic cystitis signs in client-owned cats by 89% over a 12-month period as compared with a control food.⁵

A therapeutic food can also help alleviate stress; dietary supplements L-tryptophan and hydrolyzed casein have both been shown to manage stress in cats.^6,7 These supplements have been added to Hill’s Prescription Diet c/d Multicare Feline to create Hill’s Prescription Diet c/d Multicare Feline Stress, which provides Hill’s primary solution to help prevent FLUTD in cats in potentially stressful situations (eg, relinquishment to a shelter, conflict with other pets, rehoming, new baby, travel).⁸

Shelters often have to meet the challenge of treating and preventing FLUTD in relinquished and stray cats. This challenge can be exacerbated by the stress cats may experience from leaving their familiar surroundings to be housed in a shelter. Focused dietary options such as Hill’s Prescription Diet c/d Multicare and Hill’s Prescription Diet c/d Multicare Feline Stress, coupled with behavioral counseling, can help make these cats more adoptable or able to rejoin their family.

Learn more at HillsVet.com/Urinary

• Transcellular shifts
  • Diabetes mellitus, particularly diabetic ketoacidosis, following insulin therapy (common)
  • Respiratory alkalosis due to hyperventilation caused by hypoxia, stress, anxiety, salicylate toxicity, CNS disease, fever, heat stroke, sepsis, and/or gram-negative infections
  • Refeeding syndrome
• Decreased absorption
  • Vomiting/diarrhea, particularly secondary to severe malabsorptive disease
  • Anorexia
  • Vitamin D deficiency
  • Low-phosphorus diet
  • Overdose of phosphate-binding antacids 
  • Steatorrhea
  • Following significant intestinal resection
• Increased renal excretion
  • Diabetes mellitus
  • Diuretics
  • Corticosteroids
  • Hyperadrenocorticism
  • Hypercalcemia of malignancy
  • Primary hyperparathyroidism
  • Renal tubular disorder (eg, Fanconi syndrome)
  • Hyperaldosteronism
  • Increased phosphatonins (eg, following renal transplantation [cats])
  • Eclampsia
  • Recovery from hypothermia
  • Following hepatic resection
• Miscellaneous
  • Hepatic lipidosis (cats)
• Pseudohypophosphatemia
  • Paraproteinemia

Approximately 3.5% to 7% of cats seen by veterinary behaviorists are diagnosed with CD.^3-5 Feline CD encompasses a variety of behavioral presentations that can be categorized as self-directed, oral, locomotor, vocal, or visual/hallucinatory (Table). Self-directed behavior (eg, overgrooming) is most common, followed by oral behavior (eg, pica).^3,5,6

The pathophysiology of feline CD is likely multifactorial due to the wide variety of clinical presentations. Altered function in cortico-striatal-thalamo-cortical pathways, including the basal ganglia, has been implicated in human and animal models of CD.^7,8 Varying neurotransmitter (eg, serotonin, dopamine, glutamate, acetylcholine) levels at different locations along this pathway can influence the category of CD behavior expressed.⁸ Psychopharmaceuticals to modify these neurotransmitter levels have successfully been used to treat CD in some cats.^9-11

Physical and environmental stressors have been implicated in some types of feline CD. In a study of 11 cats with psychogenic alopecia, 9 cats experienced an environmental change or stressful event (eg, separation from owner, death of an animal companion, moving to a new home) around the time of alopecia onset.⁹ Wool-sucking has also been shown to be triggered by stressful events, including being left alone for extended durations.¹² Early weaning (<7 weeks of age) has been found to increase the risk for wool-sucking and overgrooming but has not been associated with an increased risk for pica.^12-14 In another study, medical issues (eg, cardiovascular disease, neoplasia, allergies) were more prevalent in wool-sucking cats as compared with non-wool–sucking cats.¹²

Several breed predispositions have been identified for various CD behaviors, suggesting genetic factors may play a role (Table). Overgrooming and self-directed behavior are more commonly observed in Siamese, Burmese, and Oriental cats,^5,9,15 and wool-sucking appears to be more prevalent in Siamese, Birman, and crossbreed house cats.^6,12,15 Analysis of the genealogies of wool-sucking Siamese and Birman cats has indicated a dominant mode of inheritance, with possible incomplete penetrance.¹⁶ Some studies have concluded that Bengal, Burmese-type, and Siamese cats may be more likely than other breeds to exhibit pica and oral behavior,^4,5 although one study did not identify breed associations for these behaviors.¹⁴

The mean age of onset of CD is ≈2 years,⁶ although breeds that are predisposed to CD may exhibit signs at a younger age. For example, in one study, the mean age of onset of fabric-sucking in Siamese and Birman cats was 41.6 and 67.6 weeks, respectively.¹² In the previously mentioned study of 11 cats with psychogenic alopecia, 4 cats (2 Oriental and 2 domestic shorthair) exhibited fabric-sucking prior to 1 year of age.⁹

Overgrooming tends to be directed at the abdomen, flanks, back, thorax,⁹ and medial aspects of the thoracic limbs and thighs.¹⁷ However, overgrooming in these areas is not pathognomonic for psychogenic alopecia, as physical causes of overgrooming (eg, pruritus, pain) can result in the same pattern.¹⁷ In some cases, excoriation of the underlying skin may be present.

Pica may be directed at one or several objects, with shoelaces or threads, plastic, fabric, rubber, paper or cardboard, and wood being the most common.¹⁴ Cats exhibiting pica may chew on, suck on, or ingest various objects.¹⁴ In a study, cats that sucked on fabric were likely to also ingest fabric.¹⁴

Feline CD is a diagnosis of exclusion; numerous medical differential diagnoses (Table) must be ruled out before CD can be diagnosed. In a study of 21 cats referred to a veterinary behaviorist for psychogenic alopecia, medical (ie, nonbehavioral) causes of repetitive behavior were identified in 76% of the cases¹⁷; only 2 cases were identified to have behavioral causes, and 3 exhibited a combination of psychogenic alopecia and pruritus. After presumptive medical causes have been identified and treated, the repetitive behavior may persist to the same or a lesser degree, which can indicate that the physical ailment was either not the primary inciting factor or that medical and behavioral comorbidities were present.

A diagnosis of CD can be supported when physical and behavioral causes of an abnormal, repetitive behavior that interferes with a cat’s quality of life have been ruled out. To make this determination, a thorough behavior history—including but not limited to a description (ideally including a video) of the behavior, initiating factors, situations in which the behavior is likely to occur, pet owner’s response, and previous treatment attempts and their degree of success—should be obtained. Behavior history forms are available from several resources (see Suggested Reading).

Obtaining an accurate verbal history may be difficult, as pet owners may mislabel or not have witnessed their cat’s behavior. For example, cats with psychogenic alopecia are likely to be presented for hair loss rather than overgrooming because owners may not witness overgrooming. Similarly, a pet owner may not realize that the cat exhibits pica until it vomits or foreign bodies are detected on imaging or during exploratory surgery. Some CD behavior may be difficult for pet owners to describe and are subject to misinterpretation. Skin rippling associated with feline hyperesthesia may be described as itching, twitching, or a seizure by the pet owner. When possible, owners should be encouraged to record a video of their cat’s behavior. A trichogram exhibiting barbered hairs with sharp, broken ends can help differentiate between overgrooming and hair loss or poor regrowth.¹⁸

Treatment of feline CD includes educating owners, minimizing the repetitive behavior, reinforcing alternative behavior, and alleviating stress through environmental enrichment and anxiolytics.

Verbal or physical punishment (eg, yelling, swatting, scruffing) should not be used to treat CD. Because repetitive behavior often originates from stress or frustration, use of harsh verbal or physical punishment that increases the cat’s anxiety may exacerbate the disease. Moreover, cats may avoid punishment by learning to engage in the CD behavior out of the pet owner’s sight. If the cat engages in CD behavior and must be interrupted, it is best to use remote punishment not associated with the owner’s presence (eg, dropping a book to make a noise out of the cat’s sight, tossing a pillow across the cat’s line of sight to break its concentration).

Minimizing the practice of the CD behavior reduces opportunities for reinforcement of the behavior and may be necessary for the health and welfare of the cat, particularly if the behavior is self-injurious. If overgrooming or hyperesthesia results in wounds, an Elizabethan collar may be required. Similarly, cats exhibiting pica may need to be confined to a single room or cage where the environment and access to objects can be strictly controlled. Although necessary, these measures may increase the cat’s stress, which may perpetuate the CD behavior.

Preventing situations that trigger the repetitive behavior or preemptively engaging the cat in another activity before the CD behavior occurs is ideal. For example, childproof locks may help prevent a cat with pica from breaking into closets to chew on clothing or shoelaces. If bouts of overgrooming coincide with environmental stressors (eg, owner’s departure), owners can engage cats in play with a new toy before leaving. Attempts to distract the cat with food, toys, or attention while it is engaged in the repetitive behavior may inadvertently reinforce the behavior.

Positive reinforcement training should be used to teach alternative behavior and create pleasurable associations with previously stressful situations. For example, for cats that exhibit CD behavior associated with the owner’s departure, a positive emotional response may be elicited if the owner’s departure is consistently paired with a treat before the cat engages in the behavior. Cats that repetitively pace or vocalize can be taught to go to a specific spot (eg, a chair) on command to await a reward (eg, treat, play time, brushing). Directing the cat to a quiet, convenient location teaches an alternative coping strategy to mitigate the CD behavior.

In most cases, owners are unaware of the specific triggers of the behavior or the behavior occurs unexpectedly or not in the owner’s presence. In such cases, the goal of treatment should be to reduce the cat’s global anxiety and frustration through environmental enrichment and anxiolytics. Feline environmental enrichment provides a means to avoid stressful situations (eg, abundance and wide distribution of resources, including hidden or elevated spaces), mental and physical stimulation (eg, foraging toys, active play; see Suggested Reading), and opportunities to engage in normal, species-typical behavior (eg, provision of scratching posts and litter boxes). In a study of cats diagnosed with feline behavioral ulcerative dermatitis (ie, nonhealing ulcerations secondary to psychogenic pruritus), implementation of an environmental enrichment plan resulted in cessation of pruritus within 2 days and complete healing over several days depending on lesion severity; none of the cats that improved relapsed during the 12- to 24-month follow-up period.¹⁹

Treatment options to decrease anxiety include pheromones (eg, feline facial and appeasing pheromones), supplements (eg, α-casozepine, L-theanine), and pharmaceuticals (eg, tricyclic antidepressants, selective serotonin reuptake inhibitors; see Suggested Reading).

The relatively few anxiolytic efficacy studies that have been conducted for feline CD have produced varying results. For example, in a retrospective study, 5 cats exhibiting psychogenic alopecia groomed less frequently and experienced hair regrowth when treated with clomipramine (1.25-2.5 mg/cat PO every 24 hours)⁹; 3 of the 5 cats also received environmental modification to reduce stress. However, in a different prospective, double-blind, placebo-controlled study of 25 cats with psychogenic alopecia, 11 cats treated with clomipramine (0.5 mg/kg PO every 24 hours) for 56 days did not experience a significantly decreased number of grooming bouts or hair regrowth as compared with placebo-treated cats.¹¹ Mixed success has also been reported following treatment with other behavior medications (eg, amitriptyline).^9,20 These studies indicate that the response to psychopharmaceutical treatment is highly variable. Furthermore, because no medications are currently licensed by the US FDA for the treatment of feline CD, it is important to review possible adverse effects and obtain informed consent from the owner prior to use.

Prognosis for reduction in the frequency or intensity of CD behavior is fair but poor for complete resolution or cure. Owners should be informed that the goal of treatment is to improve the cat’s welfare and quality of life by limiting the risk for self-injury and increasing the amount of time engaged in pleasurable activities rather than the compulsive behavior.

Feline CD affects the well-being of both the cat and its owner and may result in relinquishment or euthanasia of the pet if not addressed. Ongoing communication with the owner is essential to increase the likelihood of compliance with the treatment plan. Because treatment response depends on many factors and may be unpredictable, frequent consultation may be needed to adjust the treatment plan.

Identifying lymph node status in mast cell tumors (MCTs) is important for determining prognosis and whether further staging is necessary. Although palpation and cytology of regional lymph nodes are often performed, their value is limited; thus, histopathology remains the gold standard.^1-3 It is generally understood that enlarged lymph nodes should be removed in all cases, but less is known regarding how to manage lymph nodes that are normal in size or nonpalpable, as well as how to definitively diagnose metastatic disease on histopathology. A recent study categorized lymph nodes as HN0 (nonmetastatic), HN1 (premetastatic), HN2 (early metastasis), or HN3 (overt metastasis), according to the degree of metastatic cell aggregates present and evaluation of lymph node architecture.⁴

In the current study, the authors aimed to assess the metastatic rate of nonpalpable or normal-sized regional lymph nodes in dogs with MCTs. Included in the study were 93 dogs with solitary cutaneous MCTs that were negative for distant metastasis. Regional lymph nodes that were nonpalpable or normal in size were removed, and clinical characteristics, including tumor size and histologic grade, were evaluated. Of the 93 dogs, 46 were found to have histologically detectable metastatic disease. The only clinical factor significantly associated with metastatic disease was a tumor diameter >3 cm.

These study findings highlight the importance of regional lymph node removal at the time of MCT removal. Lymph node status is important for staging and potential chemotherapy decision-making and may also guide the need for further staging, as MCTs tend to metastasize to the regional lymph nodes before becoming widely metastatic.⁵ Removal of metastatic lymph nodes may also provide a survival advantage.⁶ Regional lymph node removal was a high-yield test in this study; however, further investigation is needed to determine whether sentinel lymph node mapping would be a more effective method of staging.⁷

Key pearls to put into practice:

Palpation characteristics are an insensitive method for detecting metastatic disease in MCTs and many other cancers.

The use of the Patnaik 3-tier⁸ and Kiupel 2-tier⁹ histologic grading systems in this study highlights a problematic issue with the Patnaik system. Patnaik grade II MCTs are the most common MCT classification¹⁰; however, this study found discrepancies between the Patnaik grade II classification of some lymph nodes when they were compared with the Kiupel grading system. These discrepancies create a gray area in how to manage Patnaik grade II MCTs.

Removal of the regional lymph node with MCT resection may yield a high rate of metastatic disease, as seen in this study.

Larger MCTs (>3 cm) have a higher rate of nodal metastasis.

Cats are commonly affected by diabetes mellitus,^1,2 which can have a significant impact on pet owners due to the time commitment and costs associated with its management.³ Diabetic cats require a structured plan for feeding and insulin administration that owners must follow; aggressive monitoring and treatment are typically needed if diabetic remission is a goal of therapy.^4,5 Most owners of recently diagnosed diabetic cats will be experiencing drawing up and administering injections for the first time, which can be a source of fear and anxiety. Many concerns can be alleviated, though, by providing good owner education in the clinic and resources owners can access on their own (eg, handouts, videos, websites, online support groups).

In this study,* owners were surveyed regarding their perceptions about treatment and monitoring of diabetic cats. A total of 748 questionnaires predominately from the United States (43%) and United Kingdom (36%) were submitted. As compared with prior studies in which diabetic remission rates were reportedly ≤84%,^5,6 remission in this study was only reported in 18% of cats alive at the time of questionnaire completion. Fewer than 50% of owners reported their veterinarian discussing diabetic remission, use of home blood glucose monitoring, or how to recognize unstable disease. Of concern, 25% of owners reported not being taught how to draw insulin, and 27% were not taught to administer insulin. Owners also noted that websites they found on their own were the most useful resources. When owners were asked what influenced their treatment decision, the answer options “what is best for my cat” (almost 100% of respondents) and “veterinarian recommendations” (86% of respondents) were selected as the most important factors.

Approximately 70% of owners chose home blood glucose monitoring as a preferred method of monitoring; of these, 53% learned about the method online, 27% learned from their veterinarian, and the remaining 20% learned from other sources or had personal/previous experience with home blood glucose monitoring. Many owners used home blood glucose monitoring several times a day as part of a tight regulation protocol; some owners reported checking blood glucose as often as every 2 hours and ≤20 to 30 times daily. Overall, owners reportedly felt that caring for a diabetic cat had less of an effect on their daily life and relationship with their pet than they had thought it would prior to starting treatment.

Key pearls to put into practice:

At the time of diagnosis, clinicians and staff members should dedicate time to discuss all aspects of care and monitoring of diabetic cats with owners. This should include demonstrating and having owners practice proper insulin administration.

Owners are likely to seek information online. Clinicians should be ready to direct owners to accurate and useful websites.

Many owners may be interested in home glucose monitoring to help manage their diabetic cat and reduce the cost of care. This may be accomplished with blood glucose meters or continuous glucose monitors.

Periodontal disease is a common inflammatory disease in dogs. Bacteremia, bacterial metabolic products and toxins, and inflammatory mediators and immune complexes that result from periodontal disease can all have an impact on distal organ health.

This study sought to evaluate the association between periodontal disease and systemic disease, specifically renal, hepatic, and cardiac disease. Records of 136 dogs presented to a veterinary teaching hospital were retrospectively reviewed. Dogs were separated into 2 groups: those that had periodontal disease (n = 75) and those that did not have periodontal disease (n = 61). The average age of dogs in the periodontal disease group was 12.1 years, and >50% of dogs in this group weighed <22 lb (10 kg).

A significant association was found between periodontal disease and cardiac disease. Of the 75 dogs that had periodontal disease, 38 (50.67%) demonstrated cardiac signs, whereas only 2 of the 61 dogs (3.28%) that did not have periodontal disease showed these signs. Although an association between periodontal and cardiac disease was demonstrated in this study, conclusions must be tempered with the understanding that—although periodontal disease may be a risk factor for dogs predisposed to cardiac disease, particularly myxomatous mitral valve disease—a specific causal relationship cannot be proven.

No statistical correlation was found between periodontal disease and either renal or hepatic disease; however, this was determined based on clinical features rather than histopathology. Study limitations, as noted by the authors, included limited sample size, its retrospective nature, and lack of periodontal disease staging.

Evidence-based research directly connecting periodontal disease to a causal relationship with systemic disease is challenging to validate and substantiate. However, the lack of hard evidence does not negate the potential risk factor for periodontal disease, especially when the potential impact of chronic inflammation is considered.

Key pearls to put into practice:

Owners should be educated about how periodontal disease can contribute to overall health. Bacteria are present in the gingival sulcus of the teeth in a biofilm that has direct contact with the gingiva. The gingiva has a local immune response to this encroaching bacterium and its toxic products. As periodontal disease progresses, significant local effects occur and have the potential to contribute to overall systemic disease.

Although periodontal disease involves bacteria, routine dental prophylaxis in a healthy patient does not generally necessitate systemic antibiotic therapy.

Prevention of periodontal disease through regular dental care to avoid substantial local and systemic impact caused by disease is ideal. Regular dental care is particularly important for any patient with systemic disease.

Anecdotal information suggests that guinea pigs have a high prevalence of ocular issues. Guinea pigs have prominent eyes, with eyelids open at birth, relatively small third eyelids, and low tear production, which can all predispose them to conditions that affect conjunctival and corneal health.

In this study, 9 clinically normal guinea pigs and 11 guinea pigs that had clinical conjunctivitis were examined and tested to evaluate their conjunctival microflora. Conjunctival swabs were obtained from both eyes of each guinea pig for bacterial culture and susceptibility testing. Culture results revealed bacterial growth in 77% of the clinically normal guinea pig eyes and in 72% of guinea pig eyes with clinical evidence of conjunctivitis.

In the clinically normal guinea pigs, the most common bacterial isolates were Staphylococcus spp, Bacillus spp, and Streptococcus spp, all of which have been reported as part of the normal microflora of guinea pig conjunctiva. Bacteria isolated from guinea pigs with signs of conjunctivitis consisted primarily of Staphylococcus spp, Moraxella spp, Clostridium spp, Listeria spp, and Streptococcus spp. Most of the isolated bacteria were sensitive to common antibiotics used in guinea pigs (eg, enrofloxacin, doxycycline, vancomycin). No significant difference between groups was found in the number of isolated Staphylococcus spp and Streptococcus spp. One limitation of this study was the use of a general bacterial susceptibility panel; use of an ophthalmologic susceptibility panel would have been preferable.

Key pearls to put into practice:

A sterile microswab sample of the cornea and mucosal surface of the lower conjunctival fornix for culture and susceptibility testing is sufficient for determining the bacterial flora of a guinea pig with conjunctivitis.

When bacterial culture and susceptibility testing is requested for a guinea pig, the clinician should request an ophthalmologic susceptibility panel from the laboratory rather than a general antimicrobial susceptibility panel.

Bacterial growth from a conjunctival swab in a guinea pig does not automatically equate to a diagnosis of bacterial conjunctivitis. Healthy guinea pigs without clinical signs of conjunctivitis also have the potential for positive bacterial cultures.

Although pathogenic bacterial infection is a common cause of conjunctivitis in guinea pigs, infectious agents are not the only cause; vitamin C deficiency can also result in conjunctivitis in these patients. The clinician should consider all potential etiologies when diagnosing a patient.

Feline obesity is of growing concern and mirrors similar trends in humans and other pet species.^1,2 A 2006 US study reported 35.1% of cats older than 1 year to be overweight or obese, with obesity occurring most frequently between the ages of 5 and 11 years.³ Obesity in cats has been identified as a risk factor for arthritis, urinary tract disease, skin disease, diabetes mellitus, neoplasia, and hepatic lipidosis.^3-5

This retrospective study* analyzed a dataset of 19,015,888 adult cat records from clinics in the United States and Canada between 1981 and 2016 and represented 52,945,410 recorded body weight (BW) measurements. The objective of the study was to characterize BW changes over a pet’s lifespan and investigate associations between BW and breed, sex, and spay/neuter status.

When data from 1995 were compared with data from 2005, peak BW occurred between 6 and 10 years of age in neutered Siamese, Persian, Himalayan, and Maine Coon cats, then declined. When data for short-, medium-, and longhair domestic cats were evaluated, small but significant increases in mean BW were noted in spayed and neutered cats as compared with intact cats. Confounding factors (eg, diet, lifestyle, health status) were not considered in the analysis but could play a role in BW alteration over time. In addition, because this study focused on BW measurements and not body fat or BCS, conclusions could not be made regarding the prevalence of obesity in this population. Of note, 52% of cats had their BW measured only once, which suggests that BW was not routinely recorded at visits or that regular visits were not occurring. The high number of missing BW measurements suggests that this important component of feline health monitoring is routinely being missed in the clinic.

Key pearls to put into practice:

Monitoring BW is an important component of feline healthcare. Tracking changes in BW over time can help guide clinicians and owners in risk assessment for disease and in developing personalized care plans for cats.

BW is an objective measurement that can be useful in tracking the health status of an individual cat. As compared with BW, BCS is more closely correlated with representing body fat but requires staff be trained on how to obtain BCS measurements to be reliable.^6,7

Communicating with owners about their cat’s BW is an important but sometimes difficult aspect of an annual examination. A positive attitude and patient-directed speech (ie, directly addressing the cat in an empathetic and amusing manner) have been demonstrated to aid in successful clinician– owner interactions regarding weight gain in cats.⁸

Diagnostic measures of hemostasis include platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and fibrinogen degradation products. During venipuncture in humans, the shear force exerted by a needle smaller in diameter has been shown to affect platelet count but not PT or aPTT. As compared with human platelets, feline platelets have greater aggregability in response to shear stress. This prospective, observational, randomized clinical study evaluated whether needle size (22-g vs 25-g) affected routine coagulation variables in cats. Blood was sampled from the left and right jugular veins of 20 healthy, client-owned cats. Results showed no difference between the needle sizes in aPTT, platelet count, fibrinogen degradation products, or fibrinogen. PT was significantly higher when blood was drawn with the smaller diameter needle, but the degree of elevation was considered to have little clinical impact. The authors concluded that jugular venipuncture with either a 22-g or 25-g needle did not introduce any clinically meaningful difference in routine coagulation variables or platelet counts in cats.

Dog kennels can present challenges to parasite-control programs due in part to dogs of all life stages being housed in close proximity.^1,2 For instance, reactivation of some parasitic infections (eg, Toxocara canis, Ancylostoma caninum) can occur during whelping, and puppies can be a source of infection for uninfected dogs in the same location.^3,4 Although detrimental to any dog, parasitic infection can be particularly problematic for athletic dogs, as acute infection with some species can lead to anemia, and chronic infection can result in growth retardation and failure to thrive.^5,6

This study evaluated the impact of parasitism on greyhounds in Australian breeding kennels. Previous studies have reported parasite prevalence in greyhound kennels in other countries to be ≈40% to 46%.^1,7 Parasite prevalence has also been determined in other dog populations in Australia, including other breeds in breeding kennels, in which the parasite prevalence was estimated to be ≈33%.⁸ However, no information about parasite prevalence or risk factors for infection had yet been determined for greyhounds in breeding kennels in Australia.

In this study, fecal samples were collected from 721 greyhounds in breeding kennels across 5 Australian states, and questionnaires were supplied to each dog owner/trainer. Two parasitic tests were applied to each fecal sample (ie, wet malachite-stained smear, zinc sulphate centrifugation flotation), and ova/cysts were identified at the level of genus and/or species when possible. A subset of samples positive for A caninum, Giardia spp, Taenia spp, and/or Neospora/Hammondia spp underwent molecular characterization to determine which species were present. Risk factor analysis was performed using modeling techniques that accounted for the effects of individual kennels.

Total parasite prevalence was determined to be 60.3%, which is higher than what has been reported in greyhounds in breeding kennels in other countries. The parasite genera reported most frequently were Sarcocystis, hookworm (ie, Ancylostoma, Uncinaria stenocephala), Giardia, and Toxocara. The 2 major risk factors associated with parasitism were the dominant surface the dogs were housed on and the age of the dog; geographic region was also a risk factor. Dogs housed on concrete had a lower proportion of parasitism than did dogs housed on grass or sand, and adult dogs had a lower prevalence of parasitism than did juvenile dogs. The geographic region in which the kennel was located influenced the prevalence of the different parasite genera.

Key pearls to put into practice:

Kennel flooring in breeding facilities may impact overall parasite prevalence; thus, choosing surfaces that can be more easily cleaned and disinfected may help decrease parasite load.

Restricting access of juvenile dogs to adult housing areas may help prevent the spread of parasites in the kennel environment.

Recognizing which parasite species are prevalent in the geographic region in which the kennel is located may help inform best practices when designing a parasite-control program.

Animal hoarders pathologically accumulate more animals than they can properly care for. This study compared long-term outcomes for 371 cats that were surrendered to a high-quality private shelter from 14 hoarding environments. Various illnesses related to overcrowding, including upper respiratory infection, skin disease (eg, inflammation, alopecia, wounds), fleas, ear mites, and gingivitis, were common. Upper respiratory infection was significantly more prevalent in cats from institutional hoarding environments (ie, organizations advertising themselves as rescues or shelters). In 11 of the 14 hoarded groups, ≥90% of the cats were eventually adopted. The authors attributed this high success rate to manageable group sizes and managed intake, generous funding, and collaboration with community members.

This double-masked, randomized, crossover, placebo-controlled clinical trial evaluated the use of pregabalin in 8 dogs that had neuropathic pain associated with Chiari-like malformations and syringomyelia. Each dog underwent a placebo and a pregabalin treatment phase. Using a numerical scale, owners reported improved daily pain scores when dogs were treated with pregabalin. Pregabalin also significantly improved quantitative sensory testing, including mechanical hyperalgesia, cold hyperalgesia at 32°F (0°C), and cold allodynia at 59°F (15°C). In addition to its efficacy, pregabalin was well tolerated and noncumulative and had few adverse effects other than mild sedation.

The owner reported that Max was twitching and convulsing while lying awake in his bed the day before presentation. He was shaky the rest of the day and tentative in gait, and he had a similar but more severe episode of shaking the same night ≈2 to 3 minutes in duration. There was no reported salivation, vocalization, or elimination during the episode. Max had no known history of head trauma, toxin exposure, or travel and was up to date on vaccinations. Lead exposure was considered unlikely.

Max was evaluated ≈4 hours after the second episode by an emergency clinician, who suspected that Max was experiencing seizures. Physical and neurologic examinations were normal. CBC, serum chemistry profile, and urinalysis were unremarkable. Bile acid testing revealed normal preprandial bile acids (3.27 μg/mL; range, 0-4.9 μg/mL) and mildly elevated postprandial bile acids (15.89 μg/mL; range, 0-10.21 μg/mL), which were attributed to possible microvascular dysplasia, but other disorders (eg, portosystemic shunt) could not be excluded.

Max was prescribed phenobarbital (2 mg/kg PO every 12 hours) as a maintenance anticonvulsant and 2 doses of rectal diazepam (1 mg/kg per dose) for emergency seizure control and was discharged and referred to a neurologist. He was presented to the neurology service 2 days later with generalized tremors that had not responded to diazepam.

On presentation to the neurology service, Max was alert and responsive. Neurologic examination revealed whole-body, small-amplitude, high-frequency tremors that were most apparent when Max was moving or being examined (see Video). The tremors were substantially reduced when Max was sitting or lying down and stopped when he was completely at rest or asleep. The tremors resumed when he awoke and/or became active. Gait analysis revealed dysmetria (ie, hypermetric thoracic limbs) and vestibular ataxia (eg, veering, drifting, occasional stumbling). No resting nystagmus was observed, but opsoclonus (ie, pendular nystagmus with no fast phase) was observed when he was placed on his back. Postural reactions, patellar reflexes, and withdrawal reflexes were normal.

Clinical signs were localized to the cerebellum, and vestibular signs were thought to be due to involvement of vestibular components of the cerebellum (ie, flocculonodular lobe, fastigial nucleus, caudal cerebellar peduncle). The initial convulsions reported by the owner may have been a milder version of the tremors the dog later displayed.

The primary differential diagnoses were steroid-responsive tremor syndrome (SRTS) and toxicosis (eg, mycotoxicosis). Other differential diagnoses included encephalitis, brain malformation, and neurodegenerative disorders (see Related Article). Toxicity was considered less likely, as there was no known exposure to mold in the house and the patient was confined to a fenced-in yard when outside.

Routine MRI of the brain was within normal limits. CSF analysis showed normal protein content (15.7 mg/dL; range, <25 mg/dL) and a mildly elevated nucleated cell count (6 cells/μL; range, <3-5 cells/μL). Cytologic examination of a concentrated CSF sample revealed mononuclear pleocytosis composed of mostly small, mature lymphocytes (66%), with fewer reactive macrophages (26%) and nondegenerate neutrophils (8%). CSF bacterial culture was negative. Serologic testing for Borrelia burgdorferi, Anaplasma phagocytophilum, Ehrlichia canis, and Rickettsia rickettsii was negative. PCR testing of CSF for Anaplasma spp, Bartonella spp, Blastomyces dermatitidis, B burgdorferi, canine distemper virus, Coccidiodes spp, Cryptococcus spp, Ehrlichia spp, Histoplasma capsulatum, Neospora caninum, R rickettsii, Toxoplasma gondii, and West Nile virus was also negative.

Based on the lack of toxin exposure combined with the results of diagnostic testing, SRTS was strongly suspected.

Max received immunosuppressive doses of prednisone (7.5 mg [1 mg/kg] PO every 12 hours) and diazepam (0.5 mg/kg PO every 12 hours for 1 week; see Treatment at a Glance). 

At the 2-week follow-up visit, Max’s owner reported that the tremors had stopped within 2 to 3 days of discharge and gait had returned to normal during the first week of treatment. Neurologic examination was within normal limits. The prednisone dose was reduced to 5 mg PO every 12 hours for 1 month, then to 5 mg PO every 24 hours for 2 months, and finally to 5 mg PO every 48 hours for 2 months.

Max was presented for a recheck examination 6 months after the 2-week follow-up. The owner had discontinued prednisone 2 weeks prior. Because there was no sign of relapse during the treatment period or after the owner discontinued treatment, prednisone was not restarted. Max was still normal ≈3 months after the 6-month recheck.

Tremors are involuntary, somewhat rhythmic, oscillating muscle contractions and relaxations of ≥1 body part.^1-3 Tremors are common but incompletely characterized in veterinary medicine.

The terminology used to define tremor syndromes is under debate, and classification schemes are continually evolving. Veterinary classification schemes typically divide tremors into the following broad categories: physiologic or pathologic, congenital or acquired, and resting or action related.^2-4 Tremor syndromes can fall into multiple categories; for example, tremors caused by hypomyelination/dysmyelination in young springer spaniels, Samoyeds, chow chows, and other breeds are both congenital and action related.²

The most common causes of acquired, small-amplitude, high-frequency, action-related tremors are SRTS and toxicity, particularly mycotoxicosis.¹ 

SRTS is reported most commonly in small-breed dogs typically younger than 5 years.^1-3 SRTS was originally described—and appeared to be more common in—small white dogs (eg, bichon frises, Maltese terriers, West Highland white terriers), leading to the term little white shaker syndrome.^2,5,6 This term is no longer recommended, as more than half of affected dogs are not white and any breed can be affected.^1,7,8 Other terms for this condition include shaker dog syndrome, corticosteroid-responsive tremors, and acquired action-related repetitive myoclonus.²

Although its cause is unknown, SRTS is suspected to be an autoimmune disorder due to its response to corticosteroid administration. Gross histologic examination of brain tissue is often normal,⁵ but histologic findings in some dogs have shown mild, diffuse meningoencephalitis characterized by mild perivascular cuffing with lymphocytic infiltrates.²

Most patients with SRTS are presented for evaluation of tremors and incoordination. Owners may misconstrue the tremors as fear, anxiety, or shivering. As seen in Max, patients with SRTS exhibit small-amplitude, high-frequency, whole-body tremors when moving^1-3,9; these tremors typically resolve when resting or asleep. Affected dogs also frequently display signs of ocular tremors (ie, opsoclonus), cerebellar or vestibular ataxia, head tilt, absent menace, weakness, and, potentially, seizures.^2,3 Clinical signs of SRTS are indistinguishable from those of tremors due to mycotoxicosis.^2,3

A presumptive diagnosis of SRTS can be made based on signalment, clinical signs, neurologic examination findings, and exclusion of other potential causes. MRI results are usually normal in SRTS patients, but evidence of mild meningoencephalitis may be apparent.^1,7,9 CSF in SRTS patients typically contains normal to mildly elevated protein content and has a nucleated WBC count.^1,5,7-9 CSF differential cytology most often reveals lymphocytic pleocytosis.

SRTS is generally responsive to corticosteroids. Immunosuppressive doses of corticosteroids (eg, prednisone [1-2 mg/kg PO every 12 hours for 2 weeks]) often resolve tremors within a few days.^1,5-9 Once the tremors resolve, the dose should be slowly tapered to the lowest effective dose over several months as for other autoimmune disorders. Anecdotally, clinical signs are more likely to recur if treatment is tapered and discontinued before 6 months. Some patients may need to remain on low-dose treatment (eg, prednisone [0.25-0.5 mg/kg PO every 48 hours]) long-term to prevent recurrence. In rare cases, other immunosuppressive medications may be required, typically to reduce the adverse effects of corticosteroids. Affected dogs may also benefit from a short course of diazepam (0.5 mg/kg PO every 8 hours for 1 week).^1,5,9 Prognosis is excellent if disease is treated early and aggressively. Many patients can be successfully weaned off corticosteroids entirely.

Toxicosis is the second most common cause of small-amplitude, high-frequency tremors in dogs. Although many toxins have been reported to cause tremors in dogs, mycotoxins are the most commonly reported toxic cause of generalized tremors (see Related Article).^10-15 Mycotoxins are produced by Penicillium spp, Aspergillus spp, and Claviceps spp.¹⁰ The most commonly implicated mycotoxins, penitrem A and roquefortine, are produced by P crustosum and P roqueforti, respectively, although P crustosum can produce both toxins concurrently.¹⁰ Common sources of mycotoxins include garbage, compost, contaminated feed/grain, and moldy foods, particularly dairy products, bread, and nuts.^10-15

Clinical signs include generalized tremors, seizures, and muscle tremors.^10-15 As with SRTS, tremors caused by mycotoxins tend to be of low amplitude and high frequency (ie, small, fast tremors) and occur when the patient is moving but tend to resolve at rest.^10-15 Diagnosis is typically based on compatible clinical signs and exposure risk. Measurement of penitrem A or roquefortine in biologic samples (eg, GI contents) can be performed to confirm diagnosis, but testing is generally not necessary, as tremors tend to resolve within a few days.^10-15 Treatment is largely supportive with GI decontamination, IV fluids, oxygen and ventilatory support, methocarbamol, and, if indicated, anticonvulsants.^12-15 Prognosis for full recovery is excellent, particularly when treated early and aggressively. Clinical signs often resolve within 1 to 4 days of treatment, although long-term signs (eg, lasting 2-3 months) have been reported.^12-15

Generalized tremors are a relatively common neurologic disorder. Affected patients may have severe clinical signs. Fortunately, the most common causes in dogs, SRTS and mycotoxicosis, have a very good prognosis if treated early and effectively.

• Primary neurologic disease
  • Steroid-responsive tremor syndrome (ie, little white shaker syndrome)
  • Cerebellar disorders
    • Congenital action-related tremors (eg, hypomyelination/ dysmyelination)
    • Cerebellitis (infectious, immune-mediated)
    • Neoplasia
  • Idiopathic episodic tremors (eg, idiopathic head tremors, benign postural tremors [geriatric dogs])
• Toxin exposure
  • Tremorgenic mycotoxins (penitrem A and roquefortine)
  • Metronidazole intoxication (more commonly causes central vestibular dysfunction rather than tremors)
  • Other less common toxins
    • Amphetamines/pseudoephedrine
    • Bromethalin
    • Carbamates
    • Cocaine
    • Ethylene glycol
    • Heavy metals (eg, lead, aluminum)
    • Ivermectin
    • Macadamia nuts
    • Marijuana
    • Metaldehyde
    • Methylxanthines (eg, caffeine, theobromine, theophylline)
    • Organophosphates
    • Paintballs
    • Strychnine
• Endocrine/metabolic disease
  • Hepatic encephalopathy
  • Hypocalcemia/eclampsia
  • Hypoglycemia
• Infectious disease
  • Canine distemper virus
  • Rabies
• Iatrogenic disease
  • Blood transfusion reactions