February 2018   |   Volume 16   |   Issue 2

Top 5 Dietary Protein Tips

in this issue

in this issue

History-Taking

Nasal Discharge in Dogs

Common Ophthalmic Neoplasms in Dogs & Cats

Sarcoma in Animals and Humans

Tracheal Collapse in a Dog

Sponsored by

History-Taking

Shauna L. Blois, DVM, DVSc, DACVIM, University of Guelph

Alice Defarges, DVM, MSc, DACVIM, University of Guelph

Preventive Medicine

|Peer Reviewed

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History-Taking

The importance of the pet owner interview as a diagnostic tool should not be overlooked. In a human medicine study, the top differential diagnosis generated by internists after only taking the history matched the eventual diagnosis in 76% of cases.1 The quality of information gained from the interview can be enhanced through several communication techniques.2-4

Obtaining an effective history requires 5 core skills:

  • Open- and closed-ended questioning. Start with open-ended questions to obtain details on the presenting complaint in the owner’s own words, then progress to more focused closed-ended questions to clarify details (eg, duration, frequency [Table]). 
  • Reflective listening. Paraphrase parts of the owner’s story while allowing the owner to add further information, clarify points, and correct misconceptions. Reflective listening confirms the veterinarian’s desire to understand what the owner is saying. Reflective listening can also provide opportunities for the veterinarian to voice his or her interpretation of the owner’s feelings.
  • Pausing. Avoid interrupting the owner’s story.
  • Positive nonverbal communication. Use gestures such as eye contact, head nodding, and open body posture to encourage the owner to tell his or her story.
  • Empathy. Use empathic statements (eg, “It sounds like you did all that you could for Leo.”) to build trust and rapport and show the owner that he or she is being understood and heard. Empathic statements can help obtain better diagnostic information and encourage adherence to treatment, resulting in a more positive outcome. 

Good organizational skills are essential to ensuring the patient’s history is obtained clearly and efficiently. Use of an interview template can ensure no questions are missed and facilitate capturing the information in the medical record (See Medical Record Form). 

THE IMPORTANCE OF OPEN-ENDED QUESTIONS

Busy schedules may cause veterinarians to want to avoid open-ended questions for fear of lengthy conversations; however, data from human medical studies show that asking open-ended questions does not lead to lengthy answers. In one study of new patients presented to an internal medicine clinic, patients were asked, “What brings you to the clinic today?” and were allowed to speak, uninterrupted, until finished.14 Patients spoke for an average of 92 seconds before indicating they were finished, and approximately 80% of patients were finished within 2 minutes. The doctors interviewed for the study felt that the information they received in these opening statements was relevant. 

Veterinarians often interrupt pet owners during the owner interview; in one study, a median time of only 11 seconds elapsed from the onset of the owner speaking to an interruption by the veterinarian.5 Such interruptions can prevent an owner from giving important medical details and can create a barrier to building a positive relationship. 

Open-ended questions should be followed with reflective listening, which involves repeating or paraphrasing parts of the story back to the owner to verify certain details (eg, “It sounds like Leo had 2 episodes of vomiting this morning.”). Reflective listening can also allow the veterinarian to show his or her understanding of the owner’s feelings (eg, “It sounds like you are worried about how we will keep Leo comfortable after surgery.”). Reflective listening gives the owner the opportunity to verify information or correct the veterinarian if any part of the message has been misinterpreted.3,4 

STEP-BY-STEP

HISTORY-TAKING


WHAT YOU WILL NEED

STEP 1

Begin the interview by asking  the owner open-ended questions. Encourage the owner to actively participate in the interview process. As the interview progresses, gradually transition to more specific, closed-ended questions to help elicit more detailed information (Table).2,4

Table

SAMPLE OPEN- & CLOSED-ENDED QUESTIONS

Example Question Type
Tell me about …” Open
What happened next?” Open
Describe the …” Open
When did you first notice the problem?” Closed
How many times per day did it happen?” Closed
“Can you show me which leg was affected?” Closed

 

Note: Avoid questions that begin with “why” during the owner interview. Such questions may cause the owner to feel defensive or that his or her actions need to be justified.3

By starting with open-ended questions, the veterinarian is more likely to learn the range of owner concerns at the beginning of the consultation. This information can be helpful in setting the agenda  for the current visit and can help ensure that the owner does not wait to disclose a major concern or problem until the end of the visit.5 


STEP 2

Identify the chief complaint (ie, the reason the owner is presenting the patient to the clinic) by asking open-ended questions.


STEP 3

Develop the chief complaint through further open- and closed-ended questioning to encourage the owner to elaborate on the initial details. Questions should inquire about:

  • Onset, duration, frequency, severity, and location of the problem. Because specific dates can be difficult to remember, owners can be encouraged to remember landmark events (eg, holidays).  
  • Progression or improvement of the problem 
  • Factors that increase or decrease clinical signs
  • Any attempted treatment (eg, over-the-counter or prescription medications, supplements, other nonfood items) and associated outcomes

STEP 4

Obtain a body systems review to help identify localizing or nonlocalizing clinical signs, which may be related to the chief complaint or to other concerns. This review is particularly important, as clinical signs related to the primary complaint or other pathology can be documented. Check for:

  • Attitude, activity, and behavior 
  • Appetite and body condition 
  • Water intake and urination 
  • Presence of abnormalities (eg, seizures, dyspnea, vomiting, diarrhea, coughing, sneezing)
  • Skin, hair coat, and mass(es)
  • Discharge from the eyes, nose, vulva, and/or prepuce
  • Change in gait or lameness, including weakness or collapse
  • Duration of the chief complaint

Encourage the owner to fully describe any abnormalities related to body systems. For example, a description of vomiting can help distinguish episodes from regurgitation6; urinary accidents may be better classified as urinary incontinence, pollakiuria, polyuria, or other episodes, depending on the details7; and, with the appropriate details, diarrhea may be classified as originating from the small or large bowel.8


STEP 5

Perform a general overview to identify any risk factors. Questions pertaining to the patient’s lifestyle can help identify any risk factors related to the patient, the humans associated with the patient, or the patient’s environment. Using open-ended questions can help gather complete information. For example, veterinarians who pose “telling” prompts (eg, “Tell me about Molly’s eating habits over the past few days.”) can invite the owner to give more complete answers to questions9,10; in contrast, “what” questions (eg, “What food are you giving?”) often lead to more limited responses and the potential for under-reporting of the patient’s nutritional information.9 

Check for other potential risk factors, including:

  • Environment. Investigate the pet’s type of abode and home environment. In addition, ask about exposure to other animals (eg, via kennels, dog parks, recent pet acquisition, presence of sick animals in the household), which can increase infection potential. Outdoor cats have a greater chance of being exposed to trauma and/or infections. Travel outside of the local region can place a pet at risk for acquiring certain infectious diseases (eg, clinical signs of leishmaniasis may manifest up to 7 years after infection).11 Also check for exposure to human drugs (oral or topical).
  • Vaccination and parasite preventive history for each pet in the household. The likelihood  of acquiring transmissible diseases depends on the patient’s preventive history. Vaccination history can help the veterinarian more accurately interpret laboratory tests for certain infectious diseases.12 
  • Concurrent or previous illnesses, medications administered, or other interventions. Awareness of a patient’s past and current diagnoses and any treatments provided can help identify potentially related issues (eg, gastric ulceration secondary to treatment with NSAIDs). 

STEP 6

At the end of the owner interview, ask the owner to express any other concerns about the patient. This helps ensure that all issues have been heard and that all relevant information has been gathered. A complete physical examination should follow.13

Conclusion

Human medicine studies have demonstrated the importance of a thorough medical history in making accurate diagnoses. Encouraging an owner to tell his or her pet’s story increases the amount and quality of information obtained by the veterinarian during the owner interview. A detailed patient history is an important source of data in the problem-based medical approach.

References and 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.


Can Children Get Pinworms from a Pet Dog or Cat?

Can Children Get Pinworms from a Pet Dog or Cat?

Casey Barton Behravesh, MS, DVM, DrPH, DACVPM, Centers for Disease Control and Prevention, Atlanta, Georgia

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Can Children Get Pinworms from a Pet Dog or Cat?

Human pinworms (ie, Enterobius vermicularis) are nonzoonotic intestinal parasitic worms of human hosts. Humans are considered to be the only hosts of E vermicularis; therefore, human pinworms cannot originate from pets or other animals and vice versa. Like human pinworms, pinworms found in animals such as horses (ie, Oxyuris equi) or rabbits (ie, Passalurus ambiguus) are host-specific.1-3

In General1-3

  • Human pinworm infection is spread via the fecal–oral route.
  • Symptoms of human pinworm infection include itching around the anus, which can cause difficulty sleeping and restlessness; however, some infected humans may not experience any symptoms.
  • Diagnosis is made by identifying the worm or its eggs.
    • Worms can sometimes be seen on the skin near the anus or on undergarments, pajamas, or bed sheets.

Client Communication

  • Pet owners should be advised that, because pinworms are host-specific, dogs, cats, and other pets do not play a role in the spread of human pinworms.
  • Owners with questions or concerns about human pinworms should be referred to their healthcare provider.
  • Owners should be advised that strict observance of good hand hygiene—including proper handwashing, maintaining clean and short fingernails, avoiding nail-biting, and avoiding scratching the perianal area—is the most effective means of preventing human pinworm infection and/or reinfection.
  • Careful handling and frequent changing of underclothing, night clothes, towels, and bedding can also help reduce infection, reinfection, and environmental contamination. These items should be laundered in hot water, especially after each treatment of the infected individual and after each use of washcloths until the infection is cleared.

References and 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.


Nasal Discharge in Dogs

Douglas Palma, DVM, DACVIM (SAIM), The Animal Medical Center, New York, New York

Respiratory Medicine

|Peer Reviewed

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Nasal Discharge in Dogs
Clinician's Brief
Clinician's Brief
Clinician's Brief
Clinician's Brief

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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Common Ophthalmic Neoplasms in Dogs & Cats

Georgina M. Newbold, DVM, The Ohio State University

Diane Hendrix, DVM, DACVO, University of Tennessee

Ophthalmology

|Peer Reviewed

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Common Ophthalmic Neoplasms in Dogs & Cats

Neoplastic lesions can affect every tissue of the eye in both dogs and cats and can occur in the orbit, adnexal tissues (eg, eyelids, conjunctiva), and uveal and retinal tissues inside the globe.1

Orbital Tumors 

Orbital masses can cause exophthalmia with decreased ocular retropulsion, strabismus, periocular swelling, and elevation of the third eyelid (Figure 1, below). Although nonneoplastic processes (eg, cellulitis, salivary cysts) may occur, many orbital masses are neoplastic, with a reported frequency of 57.6%.2 Patients with cellulitis, such as that seen with a foreign body or orbital abscess, may present acutely and appear painful, whereas patients with neoplasia may have a more chronic history, typically with little discomfort until later stages of the disease process.

Common orbital neoplasms include carcinomas (eg, squamous cell carcinoma, adenocarcinoma), sarcomas (eg, osteosarcoma, fibrosarcoma), meningioma, and lymphoma.2   Tumors may extend from local tissues (eg, sinonasal cavities) or originate from the bony or soft tissue structures of the orbit; metastasis from distant sites occurs less often. Orbital mass diagnosis can be confirmed using a combination of imaging (eg, ultrasonography, CT, MRI) and biopsy sampling of associated tissues (Figure 2). Bony lysis is a common finding with many neoplasms.

Adnexal Tumors 

Meibomian gland adenomas (Figure 3) are the most common eyelid tumor in dogs; in cats, squamous cell carcinoma is most prevalent (Figure 4).1,3 Other tumors that affect the eyelid or conjunctival tissues include papilloma (Figure 5), melanoma, hemangioma or hemangiosarcoma (Figure 6), and mast cell tumors (Figure 7). Adnexal tumors in dogs tend to be benign, whereas many eyelid neoplasms in cats have more malignant behavior.1,3

Tumors of the Globe 

Limbal melanocytomas (Figure 8) are benign, heavily pigmented lesions that occur most commonly in German shepherd dogs and Labrador retrievers.4,5 These tumors can expand locally but do not invade the globe or metastasize. They are treated via surgical debulking with diode laser ablation.4

The most common intraocular tumor in both cats and dogs is primary uveal melanoma (Figure 9).6,7 Although these tumors frequently exhibit nonmetastatic but potentially locally invasive behavior in dogs, a greater potential for metastasis is present in cats with iridal melanoma (Figure 10). Surgical removal of the globe is curative if metastasis has not occurred.

Other primary intraocular tumors include iridociliary body adenomas (Figure 11) and medulloepitheliomas. Lymphoma is the most common secondary metastatic neoplasia seen in the eye (Figure 12).1,7 Lymphoma can present with anterior uveitis, chorioretinitis, panuveitis, diffuse iridal thickening, or a discrete uveal mass. Although peripheral lymphadenopathy or other systemic signs are often seen with multicentric lymphoma, ocular signs may be the initial presenting clinical sign.

References and 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.


Unerupted Teeth in Dogs & Cats

Michael Jennings, VMD, DAVDC, Veterinary Specialty & Emergency Center, Greater Philadelphia, Pennsylvania

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Unerupted Teeth in Dogs & Cats

In the Literature

Babbitt SG, Volker MK, Luskin IR. Incidence of radiographic cystic lesions associated with unerupted teeth in dogs. J Vet Dent. 2016;33(4):226-233.


From the Page...

If a missing tooth is encountered during a canine or feline oral examination in which the patient is awake, the tooth may be congenitally missing; may have been previously lost, fractured (with possible retained roots), or extracted; or may be unerupted (ie, either impacted or embedded beneath the gum line).

Definitive diagnosis requires dental radiography to determine the status of the tooth. If the tooth is unerupted, there is potential for cyst development, and extraction of the unerupted tooth is recommended.

In this study, the investigators sought to determine the incidence of oral cyst formation secondary to unerupted teeth. Cases were evaluated over a 3-year period; less than one-third of 213 unerupted teeth (29.1%) had radiographic evidence of cyst formation. The mandibular first premolar and mandibular/maxillary canine teeth are those most commonly reported missing and associated with cystic lesions.1,2

Dentigerous cysts form secondary to accumulation of fluid between the crown and the dental follicle, a protective layer of soft tissue that covers the enamel of an unerupted tooth. The dental follicle is usually shed during normal eruption. If the tooth does not erupt, developmental or inflammatory factors can stimulate cyst formation. Although other types of cysts can occur, dentigerous cysts were most commonly identified (71.4%). Overrepresented breeds, which accounted for 85% of cases with a histopathologic diagnosis of dentigerous cysts, included boxers, pugs, shih tzus, and Boston terriers.


...To Your Patients

Key pearls to put into practice:

1

Awake oral examinations, with evaluation for missing teeth, should be conducted in all patients. Careful attention should be paid to missing lower first premolars, particularly in brachycephalic animals.

2

If the tooth is missing, dental radiography is recommended to confirm whether the tooth is missing or unerupted. In young patients with missing teeth, dental radiographs should be obtained at the time of spaying or neutering.

3

If the tooth is unerupted, extraction to prevent future cyst formation is recommended.

4

If the tooth is unerupted and a cyst is present, extraction of the tooth and cyst lining, followed by histopathology to confirm a dentigerous cyst, is recommended.

 

5

Referral to a veterinary dental specialist is recommended for advanced cases with significant bone destruction, multiple teeth involvement, and/or potential for pathologic jaw fractures.

 

References and 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.


Feline Injection-Site Sarcoma Assessment

Timothy M. Fan, DVM, PhD, DACVIM (Oncology, Internal Medicine), University of Illinois at Urbana–Champaign

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Feline Injection-Site Sarcoma Assessment

In the Literature

Ferrari R, Di Giancamillo M, Stefanello D, et al. Clinical and computed tomography tumour dimension assessments for planning wide excision of injection site sarcomas in cats: how strong is the agreement? Vet Comp Oncol. 2017;15(2):374-382.


From the Page...

Cats appear to be uniquely vulnerable to sarcoma development as a consequence of localized irritation and inflammation following the injection of vaccines and other medical therapeutics1-3; these tumors are referred to collectively as injection-site sarcomas (ISSs). Biologically, ISSs are locally invasive and grow rapidly. The most effective treatment outcomes rely on complete gross surgical resection of macroscopic tumor burdens.4-6 As such, assessment methods for accurately defining tumor margins are of paramount importance for guiding appropriate surgical planning and maximizing long-term cure rates in affected cats.

This prospective study examined the agreement between the measurement (length and width) of ISS sizes when assessed by digital calipers (clinical method) and contrast-enhanced CT (Figure). Over a span of 11 years at a single institute, the tumor dimensions of 53 pet cats with ISSs were evaluated before surgery by a single surgeon using the clinical method and by a single radiologist using the CT method.

Clinical measurement with manual calipers (A) of an ISS involving the soft tissues overlying the right distal lateral humeral region of a cat. A transverse view with contrast-enhancing CT (B) in the same patient readily identifies a multilobulated soft tissue tumor (yellow circle) with discrete regions of peripherally enhanced vascular growth and proliferative tumor tissues.
Clinical measurement with manual calipers (A) of an ISS involving the soft tissues overlying the right distal lateral humeral region of a cat. A transverse view with contrast-enhancing CT (B) in the same patient readily identifies a multilobulated soft tissue tumor (yellow circle) with discrete regions of peripherally enhanced vascular growth and proliferative tumor tissues.

Figure Clinical measurement with manual calipers (A) of an ISS involving the soft tissues overlying the right distal lateral humeral region of a cat. A transverse view with contrast-enhancing CT (B) in the same patient readily identifies a multilobulated soft tissue tumor (yellow circle) with discrete regions of peripherally enhanced vascular growth and proliferative tumor tissues.

Clinical measurement with manual calipers (A) of an ISS involving the soft tissues overlying the right distal lateral humeral region of a cat. A transverse view with contrast-enhancing CT (B) in the same patient readily identifies a multilobulated soft tissue tumor (yellow circle) with discrete regions of peripherally enhanced vascular growth and proliferative tumor tissues.
Clinical measurement with manual calipers (A) of an ISS involving the soft tissues overlying the right distal lateral humeral region of a cat. A transverse view with contrast-enhancing CT (B) in the same patient readily identifies a multilobulated soft tissue tumor (yellow circle) with discrete regions of peripherally enhanced vascular growth and proliferative tumor tissues.

Figure Clinical measurement with manual calipers (A) of an ISS involving the soft tissues overlying the right distal lateral humeral region of a cat. A transverse view with contrast-enhancing CT (B) in the same patient readily identifies a multilobulated soft tissue tumor (yellow circle) with discrete regions of peripherally enhanced vascular growth and proliferative tumor tissues.

Figure Clinical measurement with manual calipers (A) of an ISS involving the soft tissues overlying the right distal lateral humeral region of a cat. A transverse view with contrast-enhancing CT (B) in the same patient readily identifies a multilobulated soft tissue tumor (yellow circle) with discrete regions of peripherally enhanced vascular growth and proliferative tumor tissues.

Caliper and CT methods tended to be in agreement directionally; however, CT methods consistently estimated greater tumor sizes (length and width) as compared with the clinical method. The agreement between clinical and CT methods became more divergent as a function of increasing tumor size. In addition, the characterization of ISSs as adopting irregular-shaped growth patterns (vs spheroid or ovoid) was identified more readily by CT methods.

Integration of the findings derived from both clinical and CT methods for ISS margin assessment should be considered the best clinical practice in planning the successful surgical resection of ISSs in cats.


...To Your Patients

Key pearls to put into practice:

1

Both digital caliper (clinical) and contrast-enhanced CT methods for assessment of ISS tumor dimensions tend to be in agreement and should be used in combination to maximize the success of ISS resection in cats.

2

Contrast-enhancing CT methods have the advantage of identifying regional physiologic processes, including inflammation and vascularization, which cannot be readily appreciated by caliper methods.

3

Irregular growth patterns (extending neoplastic tendrils) displayed by ISSs can be identified more easily via contrast-enhancing CT methods.

 

4

Prospective studies are required to definitively determine if a singular method (clinical vs CT) is more predictive of achieving long-term surgical cures.

References and 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.


Ciprofloxacin Use in Dogs

JD Foster, VMD, DACVIM, Friendship Hospital for Animals, Washington, DC

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Ciprofloxacin Use in Dogs

In the Literature

Papich MG. Ciprofloxacin pharmacokinetics in clinical canine patients. J Vet Intern Med. 2017;31(5):1508-1513.


From the Page...

Fluoroquinolone antibiotics are commonly used in veterinary medicine to treat susceptible bacterial infections. For large dogs, finding an antibiotic both efficacious and affordable can be challenging. Although relatively inexpensive, ciprofloxacin has variable bioavailability in healthy dogs1; less is known in patients with active infection (which may alter drug pharmacokinetics).

Dogs (n = 34) with active infections prescribed ciprofloxacin (mean dose 23.5 mg/kg PO q24h) were prospectively evaluated in a population-based pharmacokinetic study. This population-based approach can identify covariates that can alter drug pharmacokinetics (eg, presence of azotemia, age).

The study identified body weight as the only covariate to cause variability in ciprofloxacin pharmacokinetics, where larger body weights were associated with decreased plasma drug concentrations. While using an inexpensive antibiotic such as ciprofloxacin is financially appealing, such dogs have lower plasma drug concentrations, which could lead to ineffective antimicrobial therapy.

The study also evaluated plasma drug concentrations and likelihood of killing an organism based on its minimum inhibitory concentration (MIC). Ideally, a drug dosing schedule should produce a >90% probability of clinical efficacy. The Clinical Laboratory and Standards Institute (CLSI) establishes the MIC breakpoints to define a bacterial isolate to be susceptible (S), intermediate (I), or resistant (R) to a particular antibiotic. Ciprofloxacin breakpoints are unavailable for veterinary species, so the breakpoints utilized are based on human data (< 1.0 μg/ml). This study found 25mg/kg PO q24h provides >90% probability of efficacy against isolates with a MIC of 0.06 μg/mL, but only 64% probability for those with a MIC of 0.12 μg/mL and 0% probability for isolates with a MIC of 1.0 μg/ml—a MIC that would be reported as susceptible using human breakpoints. To achieve 90% probability for a MIC of 0.12 μg/mg, a dose of 50mg/kg PO q24h is needed. A dose of 10 mg/kg PO q24h did not achieve high probability for any MIC. At MICs ≥1.0 μg/mL, even 50mg/kg of ciprofloxacin has essentially 0% probability of clinical efficacy.

The human CLSI breakpoint for bacteria susceptible to ciprofloxacin is ≤1.0 μg/mL. However, this study indicated that the human breakpoint poorly predicts likely response to treatment in dogs. Veterinarians need to be aware of the actual MIC from a culture result, not simply the interpretation of S/I/R. This study can help determine if ciprofloxacin can be effective, and what dose provides a high probability of clinical success. Because large dogs have lower blood concentrations, higher ciprofloxacin dosages may need to be considered to help increase the likelihood of bacterial eradication. At ciprofloxacin MICs ≥ 0.06 μg/mL, alternative drugs should be considered, as higher MICs have a lower probability of efficacy.


...To Your Patients

Key pearls to put into practice:

1

Larger canine body weights have been shown to be associated with decreased plasma ciprofloxacin concentrations. This effect may be difficult to predict, but could lead to therapeutic drug failure. Clinicians should consider using higher dosages of ciprofloxacin or use an alternative drug in large dogs.

2

Clinicians must evaluate actual MICs from culture results, not simply the interpretation of S/I/R. For ciprofloxacin, the MIC needs to be reported at low concentrations (dilutions < 1.0 μg/mL) to be clinically helpful.

3

If culture and susceptibility testing indicate a MIC > 0.06 μg/mL, alternative drugs should be considered.

 

4

Ciprofloxacin should only be an option for infections caused by pathogens with an MIC < 0.06 ug/ml, after consideration of the implications of using an off-label drug over approved veterinary fluoroquinolones.

References and 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.


Nail Polish & Bacterial Counts in Surgery

Kristyn D. Broaddus, DVM, MS, DACVS, Veterinary Services of Hanover, Mechanicsville, Virginia

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Nail Polish & Bacterial Counts in Surgery

In the Literature

Hardy JM, Owen TJ, Martinez SA, Jones LP, Davis MA. The effect of nail characteristics on surface bacterial counts of surgical personnel before and after scrubbing. Vet Surg. 2017;46(7):952-961.


FROM THE PAGE...

For several decades, finger nail polish on gloved hands in surgery has been a controversial topic in veterinary medicine. Two landmark papers conflict on the significance of nail polish and potential contamination.1,2 Current recommendations dictate a nail length of 5 mm to 6 mm and no jewelry, nail polish, or artificial nails. These guidelines were created to minimize bacterial loads on hands in surgery, thus reducing patient morbidity and mortality from nosocomial infections.

Nine faculty members and 12 students were included in the study. Nail length, presence or absence of nail polish, duration (ie, days) of nail polish, type of surgery, dominant hand, whether nails were bitten, glove tears, time in surgery, and sample collection times were all recorded. All subjects painted both hands with nail polish and scrubbed at least twice in a one-week period. Nail polish was then removed, and subjects scrubbed again at least twice in another one-week period. A routine 5-minute scrub protocol with 4% chlorhexidine scrub was followed. The same bottle of nail polish was applied in one coat on all subjects. Samples were taken from under the nail using a moistened sterile cotton tip applicator and sterile toothpick before and after scrubbing and at the end of surgery.

Results showed the only significant factor was nail length. Nails longer than 2 mm had higher subungual bacterial counts at all times as compared with shorter nails. Presence of nail polish did not affect bacterial counts. Bacterial counts were lowest at end of surgery in all groups.


...To Your Patients

Key pearls to put into practice:

1

Surgical gloves perforate approximately 25% to 67% of the time3-5; therefore, good hand hygiene is essential. Short nails (<2 mm) can minimize the potential for infection.

 

2

Traditional chlorhexidine scrubs are preferred over iodine-based scrubs, as they are effective in the presence of small amounts of organic material and have a residual effect up to 6 hours.

 

3

Alcohol-based surgical rubs are likely to test even better, as the effects are instant and persist well beyond application. Hands (including under the nails) must be cleaned before application, as rubs are only effective on dry hands. Rubs may be applied as a sole agent as long as hands are clean.

4

Alcohol-based rubs result in healthier hands, as they do not cause abrasions from traditional scrubbing, making hands less likely to harbor bacteria.5,6

References and 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.


Tracheal Collapse in a Dog

Tracheal Collapse in a Dog

Andrew Linklater, DVM, DACVECC, Lakeshore Veterinary Specialists, Glendale, Wisconsin

Peer Reviewed

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Tracheal Collapse in a Dog

An 8-year-old neutered male Yorkshire terrier is presented for respiratory distress. The patient had been exhibiting a loud, progressive, honking cough for 18 months before presentation. The owners had attempted nebulization and coupage at home without improvement. Physical examination reveals a distressed patient with a respiratory rate of 60 breaths/min, loud upper airway stridor and stertor, and coughing. Temperature is 103.9F (39.9C), heart rate is 160 bpm, and mucous membranes are a muddy/cyanotic color. Oxygen is administered, and the patient improves enough for lateral radiography; radiographs reveal a grade III to IV tracheal collapse at the thoracic inlet and a mild interstitial pattern, most prominent in the caudodorsal region of the lungs (Figure 1).

Radiograph showing grade III to grade IV tracheal collapse and a mild interstitial pattern

FIGURE 1 Radiograph showing grade III to grade IV tracheal collapse and a mild interstitial pattern

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

Based on the information provided, how would you grade the following drugs and why?

Do Not Use Proceed with Caution Safe

Prednisone

Correct ResponseSafeMost dogs with tracheal collapse have inflammation and irritation of the tracheal mucosa, which occur with direct contact of opposing mucosal surfaces and can worsen in times of stress or excitement (ie, when respiratory rate, effort, and cough increase). Treating inflammation with glucocorticoids (eg, prednisone) is essential to help control cough, which can exacerbate the disease process. High doses may lead to muscle wasting, panting, and hepatomegaly, all of which may exacerbate clinical signs of tracheal collapse. Although it is ideal to wean prednisone over a period of days to months, some patients may require lifelong steroid therapy if underlying bronchial disease is present. Inhaled steroids (eg, fluticasone) may be an alternate therapy in select patients that can tolerate administration.1

Meloxicam

Correct ResponseDo Not UseMost dogs with tracheal collapse receive glucocorticoids on emergency presentation. Concurrent administration of NSAIDs (eg, meloxicam) is contraindicated because of high risk for GI ulceration or perforation. Other categories of sedatives and/or analgesia may be necessary in patients that require pain control; hydrocodone or butorphanol can control pain while also providing cough suppression and sedation.1,2

Doxycycline

Correct ResponseSafePoor mucociliary clearance of commensal organisms can lead to secondary bacterial tracheobronchitis. Patients with tracheal collapse or that have been exposed to groups of dogs (eg, at kennels, parks, daycare, boarding facilities) may have a higher risk for infectious tracheobronchitis (ie, kennel cough [eg, Bordetella bronchiseptica]). Although simple tracheal bacterial infections can resolve without treatment in many normal dogs, dogs with tracheal collapse may require short-term use of antibiotics. Other first-line antibiotics may include potentiated sulfonamides or azithromycin; amoxicillin–clavulanic acid has variable distribution into bronchial secretions.3,4 Antibiotics ideally should be chosen based on culture and susceptibility results.

Cephalexin

Correct ResponseDo Not UseDogs with tracheal collapse may require intermittent short courses of antibiotics due to poor mucociliary clearance of commensal organisms. However, cephalosporins generally have insufficient coverage for organisms commonly associated with tracheal infection (eg, B bronchispetica, Mycoplasma spp), and cephalexin does not have sufficient penetration into the airways and bronchial secretions.3-5 Thus, doxycycline or azithromycin may be more effective for these patients.

Hydrocodone

Correct ResponseSafeHydrocodone, a narcotic antitussive agent, is a standard therapy for tracheal collapse used to minimize recurrent episodes of coughing. Decreasing coughing can minimize recurrent tracheal inflammation that occurs with repeated mucosa–mucosa contact. Hydrocodone also provides a level of sedation and mild analgesia necessary for many patients.

Theophylline

Correct ResponseCautionAlthough methylxanthine bronchodilators have no effect on the trachea, bronchodilation may be indicated in patients with evidence of concurrent bronchitis. Small airway dilation may decrease airway pressure in the trachea in sufficient amounts to decrease signs of tracheal collapse. In addition, the phosphodiesterase-mediated anti-inflammatory effects associated with theophylline may be helpful.2 However, at high doses, theophylline can cause restlessness, tachyarrhythmias, vomiting, and/or seizures. Excess stimulation may increase the patient’s tidal volume and exacerbate tracheal collapse. In addition, because theophylline inhibits cytochrome P450, it often has clinically significant drug interactions.

Butorphanol

Correct ResponseSafeButorphanol is an opioid antitussive agent often used as a first-line therapy in patients with tracheal collapse. It can be administered orally for chronic cough suppression or via injection for sedation in an acute crisis. Opioids have been associated with improvement of dyspnea (or the feeling of “air hunger”) in humans6,7 and can relax the patient, thereby decreasing airway pressure and possibly minimizing tracheal collapse. Careful monitoring is recommended when combining butorphanol with other sedatives.

Codeine

Correct ResponseCautionCodeine is a narcotic antitussive that can be used as an alternative to hydrocodone in dogs that require either additional analgesia or additional cough suppression. Caution should be used when prescribing codeine, as many formulations are mixed with acetaminophen. Use of codeine with hydrocodone is not recommended and can cause excessive sedation.

Dextromethorphan

Correct ResponseCautionAlthough dextromethorphan is considered a non-narcotic cough suppressant,1,2 it is less effective as compared with hydrocodone or butorphanol. Due in part to the drug’s complex pharmacokinetics, it is uncommonly used to treat tracheal collapse; however, it may be considered in patients with poor response to or experiencing intolerable side effects from other antitussives.

Excessive sedation, along with other side effects (eg, hyperexcitability), may occur when dextromethorphan is combined with hydrocodone or codeine. Over-the-counter dextromethorphan may be formulated with other medications (eg, acetaminophen, codeine, pseudoephedrine, doxylamine, diphenhydramine) and thus should be prescribed as a single agent.

Acepromazine

Correct ResponseCautionAcepromazine, a phenothiazine tranquilizer, is a potent sedative available for either injection or oral administration. Although it can be used in patients with moderate-to-severe upper airway obstruction, such as tracheal collapse, acepromazine should be avoided in dogs with concurrent cardiac disease, as it can decrease cardiac output and lower blood pressure.

TRACHEAL STENTING

Patients that are severely affected, are refractory to medical management alone, or have life-threatening airway obstruction often benefit from placement of a self-expanding intraluminal tracheal stent (Figure 2). Most patients improve substantially, and survival rates are high; however, most patients require continued medical management.

Clinician's Brief
FIGURE 2 Radiograph of a patient with tracheal collapse treated with a fully deployed intraluminal tracheal stent

References and 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.


Sarcoma in Animals and Humans

Sarah Boston, DVM, DVSc, DACVS, ACVS Founding Fellow of Surgical Oncology, ACVS Founding Fellow of Oral & Maxillofacial Surgery, VCA Canada, Newmarket, Ontario

Andre R. Spiguel, MD, University of Florida

Oncology

|Peer Reviewed

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Sarcoma in Animals and Humans

Zoobiquity: Osteosarcoma in a Dog

History

A 10-year-old spayed rottweiler with a 2-week history of left pelvic limb lameness and a palpable mass over the left ilium was referred after fine-needle aspiration findings were consistent with a mesenchymal sarcoma, most likely osteosarcoma.

Clinical Signs

On physical examination, the patient continued to show mild left pelvic limb lameness. There was a 10-to-12cm hard palpable mass overlying the left ilium. The physical examination was otherwise unremarkable.

Axial (A) and coronal (B) CT images from the patient. An aggressive bone lesion arising from the left ilium, with extension to the surrounding soft tissues, can be seen.
Axial (A) and coronal (B) CT images from the patient. An aggressive bone lesion arising from the left ilium, with extension to the surrounding soft tissues, can be seen.

FIGURE 1 Axial (A) and coronal (B) CT images from the patient. An aggressive bone lesion arising from the left ilium, with extension to the surrounding soft tissues, can be seen.

Axial (A) and coronal (B) CT images from the patient. An aggressive bone lesion arising from the left ilium, with extension to the surrounding soft tissues, can be seen.
Axial (A) and coronal (B) CT images from the patient. An aggressive bone lesion arising from the left ilium, with extension to the surrounding soft tissues, can be seen.

FIGURE 1 Axial (A) and coronal (B) CT images from the patient. An aggressive bone lesion arising from the left ilium, with extension to the surrounding soft tissues, can be seen.

FIGURE 1 Axial (A) and coronal (B) CT images from the patient. An aggressive bone lesion arising from the left ilium, with extension to the surrounding soft tissues, can be seen.

Diagnosis

CBC, serum chemistry profile, and urinalysis results were unremarkable. Three-view thoracic radiographs showed no evidence of gross metastatic disease. A CT scan of the chest, abdomen, and pelvis showed an aggressive bone lesion of the left ilium, compatible with osteosarcoma, with tumor extension to the surrounding soft tissue (Figure 1). A full-body bone scan was performed. Static images were obtained 2 hours after intravenous injection of Tc99m-MDP. There was marked uptake in the area of the primary tumor (ie, the left ilium). There was also a possible metastatic lesion in the left costal cartilages; however, careful review of the CT scan showed that the increased uptake of radiopharmaceutical at that site was most likely consistent with old trauma rather than metastatic disease (Figure 2).

Bone scan image from the patient. Increased uptake of radiopharmaceutical in the left ilium (arrow) and a potential lesion in the left costal cartilage (oval) can be noted.
Bone scan image from the patient. Increased uptake of radiopharmaceutical in the left ilium (arrow) and a potential lesion in the left costal cartilage (oval) can be noted.

FIGURE 2 Bone scan image from the patient. Increased uptake of radiopharmaceutical in the left ilium (arrow) and a potential lesion in the left costal cartilage (oval) can be noted.

FIGURE 2 Bone scan image from the patient. Increased uptake of radiopharmaceutical in the left ilium (arrow) and a potential lesion in the left costal cartilage (oval) can be noted.

Treatment

Left iliectomy and stereotactic radiosurgery were suggested to provide curative-intent local control of the tumor. Palliative radiation was also discussed. The owners elected iliectomy and preservation of the left pelvic limb; the left ilium was resected via sacroiliac disarticulation (Figure 3), and the left acetabulum and left pelvic limb were preserved. Postoperative radiographs showed adequate tumor removal (Figure 4).

Intraoperative image of iliectomy. The osteotomized ilium is grasped with bone-holding forceps after disarticulation of the sacroiliac joint. The exposed left sacroiliac joint is visible at the level of the sacrum (SI).
Intraoperative image of iliectomy. The osteotomized ilium is grasped with bone-holding forceps after disarticulation of the sacroiliac joint. The exposed left sacroiliac joint is visible at the level of the sacrum (SI).

FIGURE 3 Intraoperative image of iliectomy. The osteotomized ilium is grasped with bone-holding forceps after disarticulation of the sacroiliac joint. The exposed left sacroiliac joint is visible at the level of the sacrum (SI).

FIGURE 3 Intraoperative image of iliectomy. The osteotomized ilium is grasped with bone-holding forceps after disarticulation of the sacroiliac joint. The exposed left sacroiliac joint is visible at the level of the sacrum (SI).

Ventrodorsal postoperative radiograph showing the removal of the affected portion of the left ilium
Ventrodorsal postoperative radiograph showing the removal of the affected portion of the left ilium

FIGURE 4 Ventrodorsal postoperative radiograph showing the removal of the affected portion of the left ilium

FIGURE 4 Ventrodorsal postoperative radiograph showing the removal of the affected portion of the left ilium

Outcome

The patient recovered well from surgery in the intensive care unit. She was managed postoperatively with fentanyl (2-5 g/kg/hr CRI) and meloxicam (0.1 mg/kg IV q24h). The dog was walking well with minimal support within 24 hours and was discharged 48 hours postoperatively on meloxicam (0.1 mg/kg PO q24h) and tramadol (3 mg/kg PO q8-12h).

The specimen was inked to assess the margins and submitted for histopathology. Histopathology confirmed a diagnosis of osteosarcoma. The mitotic index was 32 mitotic figures per 10 high-power (400) fields, with moderate-to-marked anisocytosis and anisokaryosis. The margins of excision were complete. Chemotherapy with single-agent carboplatin (6 doses at 300 mg/m2 IV) was initiated and was well tolerated without complication. At 136 days postsurgery, the patient showed no evidence of local recurrence or metastatic disease on pelvic and thoracic radiographs, respectively, and was ambulating well (see Video).

Related Articles

Zoobiquitous Medicine
Video of the patient ambulating with minimal support one day postsurgery

Pelvic Chondrosarcoma & Hemipelvectomy in a Man

HISTORY

A 36-year-old otherwise healthy man with a history of multiple hereditary exostoses (MHE) noticed a painful mass over the right ilium that had slowly enlarged over the past year. He was referred to a musculoskeletal oncologist and presented with previously obtained radiographs.

CLINICAL SIGNS

On physical examination, the patient was pleasant and in no acute distress. He had a large nonmobile mass over the right hemipelvis. He was able to ambulate normally without any deficits. The rest of the examination was otherwise unremarkable.

Anteroposterior radiograph showing a large mineralized mass with poorly defined margins and a wide zone of transition arising from the right ilium
Anteroposterior radiograph showing a large mineralized mass with poorly defined margins and a wide zone of transition arising from the right ilium

FIGURE 1 Anteroposterior radiograph showing a large mineralized mass with poorly defined margins and a wide zone of transition arising from the right ilium

FIGURE 1 Anteroposterior radiograph showing a large mineralized mass with poorly defined margins and a wide zone of transition arising from the right ilium

DIAGNOSIS

Previously obtained anteroposterior pelvic radiographs (Figure 1) showed a large, poorly defined, mineralized lesion involving the right ilium. Because of the patients physical examination results, history of MHE, and radiographic findings, a secondary chondrosarcoma of the right ilium was suspected. Further diagnostic evaluation, including a CT scan (Figure 2) and MRI of the pelvis, were obtained to further characterize the lesion and begin surgical planning.

Axial CT images showing a large mass arising from the right ilium with a significant soft-tissue component in both the inner and outer tables of the pelvis
Axial CT images showing a large mass arising from the right ilium with a significant soft-tissue component in both the inner and outer tables of the pelvis

FIGURE 2 Axial CT images showing a large mass arising from the right ilium with a significant soft-tissue component in both the inner and outer tables of the pelvis

FIGURE 2 Axial CT images showing a large mass arising from the right ilium with a significant soft-tissue component in both the inner and outer tables of the pelvis

Because the lungs are the most common site of metastasis in cases of chondrosarcoma, staging was determined via bone scan and chest CT, which confirmed that there were no other sites of disease. Staging was determined to be Enneking Stage IB; prognosis was good overall. Core needle biopsy confirmed low-grade chondrosarcoma.

Treatment

Low-grade secondary chondrosarcoma with no other sites of disease is treated definitively with resection when possible. Neoadjuvant treatments (eg, radiation, chemotherapy) are of limited value and used only in palliation with limited success.1-3 Because of the patients age and good prognosis, and no need for adjuvant treatment if a negative margin could be achieved, reconstruction was elected to restore the pelvic ring in the setting of an iatrogenic disruption. The right ilium was resected by cutting through the sciatic notch toward the anterior inferior iliac spine and cutting through the sacral ala posteriorly to ensure a negative margin (ie, internal hemipelvectomy), which allowed for preservation of the right acetabulum and right hindquarter (Figures 3 and 4). Reconstruction was performed using lumbopelvic fixation and a double-barrel vascularized free fibula autograft harvested from the ipsilateral leg (Figure 5). Postoperative radiographs showed resection and reconstruction (Figure 6).

OUTCOME

The patient recovered well from surgery. Pain was controlled using a standard lumbar epidural immediately postoperatively. Two days postoperatively, the patient was doing well and the epidural was weaned. Through reconstruction and stabilization of the pelvic ring, the patients recovery was significantly advanced. He was discharged 5 days after surgery on oxycodone (10 mg PO q4-6h as needed for pain) and low-molecular weight heparin for thromboprophylaxis. To protect his construct, he was made toe-touch weight bearing for 3 months.

The patient was seen for surveillance, including radiographs of the pelvis and a CT scan of the chest, every 3 months for 2 years. At 3 years postoperation, surveillance is performed every 4 months, then every 6 months for years 4 and 5 postoperation. After 5 years postoperation, he is considered cured. Because of his history of MHE and increased risk for subsequent secondary chondrosarcomas arising from prior osteochondromas, he will continue to be seen every year for clinical examination, pelvic radiographs, and any imaging of painful or enlarging osteochondromas.

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

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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.


Top 5 Pet Food Protein Principles

Rebecca Remillard, DVM, PhD, DACVN, Veterinary Nutritional Consultations

Michelle Evason, DVM, BSc, DACVIM (SAIM), University of Prince Edward Island & Veterinary Internal Medicine & Nutrition Consultations

Nutrition

|Peer Reviewed

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Top 5 Pet Food Protein Principles

Protein is an essential dietary component for cats and dogs. However, questions from pet owners about protein content in pet food can cause difficulties for clinicians.

This is largely due to conflicting recommendations about how much protein is needed for certain life stages and specific medical conditions. Further, pet owner and veterinary attention is frequently drawn to the protein value provided on the food product label, despite lack of a clear understanding about how that number is derived or should be communicated.

To have an informative discourse with pet owners and improve dietary recommendations, clinicians should understand the following 5 important points regarding dietary protein.

1

The crude protein number on a pet food product label is a calculated estimate.

Although the term protein is easiest to refer to on the product label, this term actually refers to a calculated estimate. As such, product labels typically list crude protein.

The protein number (% as fed) is based on a laboratory determination of the total nitrogen content of the food, which is then divided by the average nitrogen content of proteins (ie, 16%).1 Not all nitrogen content in a food/product is in the form of protein; dietary ingredients (eg, carbohydrates, fat, fiber, supplements) contain nonprotein nitrogen that contributes to the total estimate for crude protein. Pet food labels typically list only the guaranteed minimum crude protein, so this value should not be taken as the actual protein content in the product. Understanding how the crude protein value is determined and expressed on the product label should help reduce the emphasis placed on this number by pet owners when comparing products or as a determinant of diet quality.

CONSIDER THIS

In 2007, a compound called melamine was added to wheat gluten and rice protein concentrate to presumably raise the crude protein content of those ingredients and achieve a higher sale price from suppliers.2 Melamine contains 67% nitrogen by weight but no protein.3

2

Animals require essential amino acids, not protein, from their diet.

Specific essential amino acids (not dietary protein) are required by each species to support growth, maintenance, gestation, and lactation and to avoid disease. After consumption and digestion of dietary proteins, animals use the essential amino acids and synthesize nonessential amino acids for serum proteins, muscles, and other necessary nitrogenous compounds the body requires. The crude protein number on the pet food label does not provide any information regarding concentration, ratio, or digestibility of the essential amino acids in the product.

Related Articles The Dreaded Question: What Should I Feed My Pet? Diets for Each Life Stage

It is important for clinicians to understand and explain to pet owners that there is no perfect protein ingredient for dogs or cats. In fact, a variety of protein ingredients are needed to meet the essential amino acid requirements. Therefore, pet food products may have individual synthetic amino acids (eg, methionine, taurine) added to meet unique feline or canine requirements when the protein ingredient(s) is low or devoid of essential amino acids.

CONSIDER THIS

A dry pet food with a product label minimum crude protein of 35% exceeds that recommended for both canine and feline growth; however, if the product does not contain the essential amino acid taurine or a sufficient concentration of arginine, a puppy will do poorly and a kitten will not survive. The crude protein number reveals nothing about taurine or arginine content. High-protein foods do not necessarily meet essential amino acid requirements any better than do low-protein foods.

3

Protein adequacy can only be assured through standardized feeding trials or nutritional review.

The nutritional adequacy of a product (and its protein) can be evaluated through standardized animal feeding trials, which measure protein bioavailability. The Association of American Feed Control Officials (AAFCO) is often cited for its published feeding protocols.4 A food fed for 6 months as the sole diet to adult dogs (and with certain biologic criteria met) is allowed the claim of nutritionally complete and balanced as substantiated by feeding studies.4 Identifying this statement on a product label should provide pet owners additional assurances regarding overall product quality, as it verifies through standardized testing that the amino acid content was bioavailable and adequate for a healthy pet outcome. None of these assurances can be made through the crude protein number.

Veterinary nutritionists often disregard the crude protein value listed on the pet food product and instead focus on amino acid content, which they will calculate as a percentage of the essential amino acid recommendations suggested by the National Research Council (NRC) or AAFCO for the various life stages (growth, gestation/lactation, maintenance).5 Listing specific amino acid information is not possible on pet food labels due to space constraints. However, pet food manufacturers can choose to list amino acid content online or in company product guides.

4

Pet food protein recommendations are suggested ranges.

Dietary protein concentrations recommended by NRC and AAFCO include a margin of safety to account for known negative ingredient interactions, losses, and bioavailability uncertainties across the variety of ingredients used by manufacturers.

NRC has 2 types of nutrient recommendations: minimum requirements (MR; ie, the amount needed if the nutrient is readily bioavailable to the animal) and recommended allowances (RA; ie, the greater amount needed when bioavailability is reduced by known food interactions). The RA value is equal to or higher than the MR value; for example, although the NRC protein MR for healthy adult cats is 40 g/Mcal, the RA is 50 g/Mcal because dietary protein sources are not 100% bioavailable from the food.

Table

Current NRC & AAFCO Crude Protein Recommendations

  NRC Crude Protein Minimum Requirement (MR)in g/Mcal NRC Crude Protein Recommended Allowance (RA)in g/Mcal AAFCO Crude Protein in g/Mcal
Canine Adult 20 25 45
Canine Growth 45 56 56
Feline Adult 40 50 65
Feline Growth 45 56 75

AAFCO, which operates independently of the NRC, generally has a wider safety margin on pet food protein content for adult dogs and cats.

Neither NRC nor AAFCO values should be mistaken as the minimum requirement for an animal, nor should they be interpreted as optimal. Multiple factors can impact desired protein content (eg, food digestibility and amino acid content, individual variation, disease processes), and an understanding of terminology and requirements is needed before veterinarians make a protein determination for a specific patient.

There is a wide range in protein values (15%-60% dry matter basis) listed and recommended by various pet food companies, even for similar products intended for the same life stage and sold by the same company.5 These values are typically higher than those recommended by NRC and AAFCO, even though increased protein is neither better nor is there a demonstrated nutritional need for it.

CONSIDER THIS

A patient with high BUN but normal creatinine (and SDMA) and normal kidney function on urinalysis is eating an unnecessarily high protein (>30% dry matter basis) diet relative to its need. The pet's BUN indicates that the excess dietary protein is being metabolized to urea by the liver and then excreted from the body via kidneys, demonstrating that feeding excess (ie, unneeded) dietary protein is readily eliminated from the body within hours of consumption. Because protein ingredients are a major determinant of pet food price, the unnecessarily high-protein products will cost more to feed.

5

Protein recommendations for dogs and cats with various medical concerns differ. The decision to adjust dietary protein concentration should be based on current protein intake.

In many cases (eg, weight loss, osteoarthritis, feline diabetes, feline hyperthyroidism, senior pets with decreased protein metabolism), a protein level above AAFCO recommendations may be desirable.6,7 In contrast, there are medical conditions for which protein levels closer to NRC RA or MR would be helpful (eg, late-stage liver or renal disease).8 Clinicians should understand that for any medical condition, increasing or decreasing protein intake should be relative to the patients current protein intake not relative to NRC or AAFCO values. This underscores the significance of a dietary history.

Of importance, neither NRC nor AAFCO recommend specific nutrient levels for medical or health-related conditions. Recommended amounts of specific nutrients of concern (eg, fat, potassium) for medical conditions are typically set by nutritionists and allied specialists and are based on known specific disease processes. Thus, the recommended dietary concentrations for particular medical conditions will vary among pet food manufacturers and individual specialists.

For example, low-protein therapeutic diets (eg, those marketed for kidney conditions, liver conditions, or uroliths) designed for long-term feeding typically are at or above the NRC crude protein RA9 and use highly digestible (>80%) ingredients with good amino acid profiles (eg, egg, liver, whey). This is done intentionally to ensure that essential amino acid needs are met while offering a lower total nitrogen (ie, crude protein) load to reduce impact on various body organs.

CONSIDER THIS

Diets with 10% dry matter protein that are properly formulated to first meet the essential amino acid needs have been safely fed to dogs for decades with poor kidney or liver function (eg, IRIS Stage 4, Dalmatians with urate urolithiasis, dogs with hepatic encephalopathy).

Conclusion

There is no single perfect protein value for all pets or life stages. The following tips and an awareness of concurrent medical concerns can help guide an appropriate veterinary team response to common pet owner queries about protein needs:

  • Suggest a range of crude protein values rather than a specific number based on the pet's life stage according to NRC (RA) or AAFCO recommendations. It may be helpful to emphasize to pet owners that high protein intake has not been shown to be medically superior in healthy pets. High dietary protein intake does not increase muscle mass in the absence of exercise.
  • Explain the difference between food products that meet current recommendations through feeding trials and nutritional review versus through those said to meet nutrient levels through analytical methods.
  • Examine the patient, noting the current diets crude protein value, and assess muscle mass and serum total protein, albumin, WBC and RBC counts, and hemoglobin. This information (if within normal limits) will suggest adequate protein intake.

In addition, asking pet owners about their concerns regarding protein concentrations can lead to further discussion about nutrition and will emphasize the shared goal of maximizing pet health.

Drs. Remillard and Evason are also advisors with Rayne Clinical Nutrition.

References and 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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