NAVLE Dermatology: High-Yield Skin Conditions and Diagnostics

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-11

Key Takeaways

• Accurate dermatologic diagnosis hinges on distinguishing primary lesions (macules, papules, vesicles, pustules) from secondary lesions (scale, crust, erosion, ulcer, excoriation, lichenification, alopecia), as primary lesions indicate etiology while secondary lesions often obscure it.
• Cytology is a rapid, first-line diagnostic tool for identifying infectious organisms (bacteria, yeast), inflammatory cells, and neoplastic cells, particularly useful for exudative lesions, pustules, nodules, and draining tracts.
• Skin scrapings, differentiated into superficial (for Sarcoptes, Cheyletiella) and deep (for Demodex), are crucial for ectoparasite diagnosis, especially in cases of alopecia and pruritus, with multiple sites increasing sensitivity.
• Dermatophyte culture using Dermatophyte Test Medium (DTM) is the gold standard for confirming ringworm, indicated by a color change to red, though Wood's lamp screening is limited to Microsporum canis and prone to false negatives.
• Skin biopsy is indicated for definitive diagnosis of neoplasia, autoimmune disease, vasculitis, and non-healing lesions, requiring careful selection of early primary lesions and submission of samples in 10% neutral buffered formalin for histopathologic interpretation.
• Pruritus workup prioritizes ruling out ectoparasites (flea combing, skin scrapings) and secondary infections (cytology) before pursuing atopic dermatitis or food allergy via strict dietary elimination trials, while alopecia evaluation differentiates inflammatory from non-inflammatory causes, guiding endocrine or infectious workups.

This article reviews the dermatologic conditions and diagnostic techniques most frequently tested on the North American Veterinary Licensing Examination (NAVLE). It serves veterinary students preparing for board examination, with a cross-species focus spanning small animal, equine, and food animal practice. The content emphasizes lesion recognition, differential diagnosis, and diagnostic decision-making instead of treatment protocols.

The NAVLE assesses clinical reasoning across multiple content areas, and dermatology appears consistently within the medicine and diagnostic domains. The examination structure and content domains are defined by the International Council for Veterinary Assessment, and candidates should review the official NAVLE candidate information for current specifications on question distribution and scoring. This article organizes the highest-yield material into lesion-based patterns, diagnostic technique selection, and species-specific presentations that recur across examination forms.

At a Glance

Structure and Function of the Integument

The skin comprises epidermis, dermis, and hypodermis, with adnexal structures including hair follicles, sebaceous glands, and apocrine glands. The epidermis maintains a stratified architecture with basal, spinous, granular, and cornified layers. Keratinocyte migration from basal layer to stratum corneum takes approximately 14 to 21 days in dogs, a timeline relevant to interpreting biopsy findings and response to therapy.

The dermis provides structural support through collagen and elastin fibers embedded in ground substance. The superficial dermis contains the papillary layer with its capillary loops, while the deep reticular layer houses larger vessels and adnexal structures. The hypodermis consists of adipose tissue and loose connective tissue, anchoring the skin to underlying structures.

Hair follicle cycling proceeds through anagen, catagen, and telogen phases. Dogs and cats have compound follicles with multiple hairs emerging from a single orifice. Follicular synchronization varies by species and body region, which affects trichography interpretation. Seasonal shedding patterns reflect photoperiod influences on follicle cycling, particularly pronounced in species kept outdoors.

The skin functions as a mechanical barrier, thermoregulatory organ, and immunologic sentinel. Langerhans cells in the epidermis process and present antigen, while dermal mast cells, macrophages, and T lymphocytes participate in cutaneous immune responses. The skin's lipid bilayer and antimicrobial peptides provide innate defense against microbial colonization. Disruption of any component predisposes to secondary infection, which explains why pruritic diseases frequently present with concurrent bacterial or yeast overgrowth.

Lesion Classification and Morphology

Accurate lesion identification forms the foundation of dermatologic diagnosis. Primary lesions develop directly from the disease process, while secondary lesions result from self-trauma, infection, or chronicity. The distinction matters because primary lesions point toward etiology, whereas secondary lesions often obscure the underlying process.

Primary lesions include macules, flat color changes less than 1 cm in diameter, and patches, which exceed 1 cm. Papules are elevated solid lesions under 1 cm, while plaques are flat-topped elevations larger than 1 cm. Nodules are solid elevations exceeding 1 cm that extend into the dermis or hypodermis. Vesicles and bullae are fluid-filled elevations under and over 1 cm respectively, and their presence suggests autoimmune or viral etiologies. Pustules contain neutrophils or eosinophils and indicate pyoderma, sterile pustular dermatosis, or certain parasitic conditions. Wheals are transient dermal edema from urticaria or hypersensitivity reactions.

Secondary lesions include scale, crust, erosion, ulcer, excoriation, lichenification, and alopecia. Scale represents abnormal stratum corneum accumulation, either dry or greasy. Crusts form from dried serum, pus, or blood overlying disrupted epidermis. Erosions are partial-thickness epidermal loss, while ulcers extend through the basement membrane into the dermis. Excoriation indicates self-trauma, typically from pruritus. Lichenification describes thickened, accentuated skin markings from chronic inflammation. Alopecia may be primary from follicular disease or secondary from self-trauma or endocrine dysfunction.

Lesion distribution and configuration provide additional diagnostic information. Symmetric alopecia suggests endocrine disease, while asymmetric or multifocal patterns favor infectious or immune-mediated processes. Linear lesions may indicate contact dermatitis or dermatophytosis. The MSD Veterinary Manual provides detailed descriptions of lesion morphology and differential diagnoses organized by pattern, which serves as a useful reference for correlating physical findings with likely etiologies.

Diagnostic Technique Selection

Diagnostic testing follows a logical sequence based on lesion type and suspected etiology. Cytology, skin scraping, trichography, dermatophyte culture, and biopsy each answer specific questions, and selecting the appropriate test improves diagnostic yield while controlling cost.

Cytology provides rapid identification of infectious organizms, inflammatory cell types, and neoplastic cells. Collection methods include impression smears for exudative lesions, acetate tape preparations for scale and superficial debris, and fine-needle aspiration for nodules. Impression smears suit moist lesions, pustules, and ulcers. Tape preparations capture superficial bacteria, yeast, and keratinocytes and work well for scaling or greasy skin. Fine-needle aspiration targets nodules and masses, distinguishing inflammatory from neoplastic processes. Cytologic interpretation should quantify organizms per high-power field and characterize the inflammatory infiltrate. Neutrophilic inflammation with intracellular bacteria supports bacterial pyoderma, while eosinophilic inflammation suggests hypersensitivity, parasitic, or neoplastic processes.

Skin scrapings detect ectoparasites and should be performed with a scalpel blade held perpendicular to the skin surface. Superficial scrapings collect stratum corneum and upper epidermis, adequate for Sarcoptes scabiei and Cheyletiella species. Deep scrapings penetrate until capillary bleeding occurs, necessary for Demodex mites residing in hair follicles. Multiple sites increase sensitivity, particularly for sarcoptic mange where mites are sparse. Mineral oil on the blade and collection slide preserves specimens and facilitates visualization.

Trichography examines plucked hairs under microscopy, assessing hair shaft structure, root morphology, and stage of follicle cycling. Broken or frayed hair tips indicate self-trauma. Dysplastic shafts suggest follicular dysplasia or dermatophytosis. The presence of anagen versus telogen roots helps differentiate endocrine alopecia from inflammatory follicular disease. Dermatophyte spores may be visible on hair shafts, though negative trichography does not exclude infection.

Dermatophyte culture using Dermatophyte Test Medium (DTM) remains the standard for confirming ringworm. The medium contains phenol red indicator that turns red with alkaline metabolites produced by dermatophytes, while saprophytic contaminants typically do not change the color. Growth appearance and microscopic morphology of conidia confirm the species. Wood lamp examination screens for Microsporum canis, which fluoresces apple-green on infected hairs, but false negatives occur in up to 50 percent of cases and other dermatophytes do not fluoresce.

Skin biopsy provides definitive diagnosis for neoplasia, autoimmune disease, vasculitis, and conditions where cytology and culture are non-diagnostic. Biopsy site selection critically influences yield. Choose primary lesions, avoid excoriated or ulcerated areas unless the disease targets those regions, and include surrounding normal skin. Multiple biopsy sites increase diagnostic confidence. The MSD Veterinary Manual describes biopsy technique and histopathologic interpretation in detail, emphasizing the importance of submitting samples from representative lesions with complete signalment and clinical history.

Clinical Approach to Pruritus

Pruritus is among the most common dermatologic presentations in small animal practice. The diagnostic sequence begins with a thorough history, including onset, progression, seasonality, response to previous therapies, and signalment. Pruritus must be distinguished from pain, self-trauma secondary to boredom, and neurologic paresthesia. A dog that licks its paws when alone but stops when distracted may have a behavioral component, whereas a dog that scratches during examination has organic pruritus.

The physical examination should map the distribution of lesions. The classic distribution patterns carry diagnostic weight. Ventral abdomen, axillae, and paws suggest environmental allergy. Dorsal lumbosacral pruritus with tail head involvement points to flea allergy dermatitis. Pinnal and pedal involvement in a young dog suggests sarcoptic mange. Otitis externa with concurrent pruritus supports atopic dermatitis or food allergy.

The minimum database for pruritus includes cytology of any exudative or erythematous lesion, skin scrapings, and flea combing. Cytology distinguishes bacterial from yeast overgrowth and guides initial antimicrobial selection while the underlying cause is pursued. Skin scrapings should be performed even when lesions are not obviously papular, because sarcoptic mites can be present with minimal visible change. Flea combing of the dorsal lumbosacral area documents flea feces, which appear as red-brown debris that bleeds onto moistened paper.

Food allergy is diagnosed by strict dietary elimination trial, not by serology or hair testing. The trial requires a novel protein and novel carbohydrate source, or a hydrolyzed diet, fed exclusively for 8 to 12 weeks. All treats, flavored medications, and chew toys must be withdrawn. Improvement during the trial supports food allergy, and rechallenge with the original diet confirms it. Atopic dermatitis is a diagnosis of exclusion after ectoparasites, dermatophytosis, bacterial and yeast infection, and food allergy have been ruled out.

Feline pruritus presents differently. Cats often overgroom instead of scratch, producing symmetric alopecia without visible lesions. The differential includes flea allergy dermatitis, food allergy, atopic dermatitis, and psychogenic alopecia. A flea control trial using an adulticide with proven efficacy in the region is the first step, because flea allergy is the most common feline hypersensitivity. Response to strict flea control within 4 to 6 weeks supports the diagnosis.

Diagnostic Approach to Alopecia

Alopecia requires a different reasoning pathway because pruritus may be absent. The first decision point separates alopecia with intact skin from alopecia with inflammation, scaling, or crusting. Inflammatory alopecia directs investigation toward folliculitis, dermatophytosis, demodicosis, and autoimmune disease. Noninflammatory alopecia suggests endocrine disease, pattern alopecia, or post-clipping alopecia.

The diagnostic plan for noninflammatory alopecia begins with a minimum database that includes complete blood count, serum biochemistry, and urinalysis. Thyroid testing in dogs should include total thyroxine (T4) and canine thyroid-stimulating hormone (cTSH). A low T4 with elevated cTSH supports hypothyroidism. A normal T4 effectively rules out hypothyroidism in most dogs. Adrenal function testing is indicated when clinical signs suggest hyperadrenocorticism, including polyuria, polydipsia, panting, and a pot-bellied appearance. The ACTH stimulation test and low-dose dexamethasone suppression test each have utility, and the choice depends on whether the clinician also needs to distinguish pituitary from adrenal disease.

Sex hormone imbalances are uncommon but should be considered in intact animals. Castration-responsive alopecia in intact male dogs and ovarian imbalance in intact females resolve after gonadectomy. Alopecia X, also called adrenal hyperplasia-like syndrome, occurs in plush-coated breeds such as Pomeranians and Chow Chows. It is a diagnosis of exclusion, and skin biopsy shows characteriztic flame follicles and follicular atrophy.

Dermatophytosis can mimic endocrine alopecia, particularly in cats and in young or immunocompromised animals. Wood's lamp examination identifies Microsporum canis in approximately 50% of cases, and false negatives occur. Fungal culture on dermatophyte test medium remains the diagnostic standard. The MSD Veterinary Manual dermatology reference provides species-specific guidance on sample collection and interpretation of culture results.

Skin Biopsy Technique and Interpretation

Skin biopsy is indicated when the diagnosis remains unclear after noninvasive testing, when lesions are progressive despite therapy, or when autoimmune disease is suspected. The clinician must select appropriate lesions. Early primary lesions, such as intact vesicles, pustules, and papules, provide the most diagnostic information. Chronic lesions show secondary changes that obscure the underlying process. Multiple biopsy sites are preferred, and the clinician should sample lesions of different ages.

Biopsy technique affects diagnostic yield. A 6 to 8 mm punch biopsy is appropriate for most lesions. The sample should be handled gently to avoid crush artifact. Suturing the biopsy site is preferred to stapling in areas of thin skin. Samples should be placed in 10% neutral buffered formalin at a ratio of at least 10 parts fixative to 1 part tissue. The submission form must include signalment, lesion description, duration, distribution, and current medications, because glucocorticoid administration can alter histologic interpretation.

Histopathologic patterns guide the differential diagnosis. Interface dermatitis with apoptotic keratinocytes suggests erythema multiforme or cutaneous lupus erythematosus. Intraepidermal pustules with acantholytic keratinocytes support pemphigus foliaceus. Folliculitis with furunculosis and fungal spores within hairs confirms dermatophytosis. The pathologist's report should be correlated with clinical findings, because some diseases show overlapping histologic features.

Diagnostic Testing for Infectious Skin Disease

Cytology is the first-line test for suspected bacterial or yeast infection. Samples are obtained by impression smear, acetate tape preparation, or swab. Staining with Diff-Quik or Wright's stain allows identification of cocci, rods, and Malassezia organizms. The presence of intracellular bacteria supports active infection instead of surface contamination. Rods, particularly Pseudomonas species, warrant culture and susceptibility testing because they often carry multidrug resistance.

Dermatophyte culture requires collection of hairs and scales from the leading edge of lesions. Plucked hairs are preferred to scraped scales because the fungus invades the hair shaft. The sample is pressed onto dermatophyte test medium and incubated at room temperature for up to 21 days. A color change from yellow to red indicates alkaline metabolites, but this occurs with saprophytic fungi as well. Microscopic examination of the colony is required to confirm Macroconidia morphology.

Bacterial culture is indicated when cytology shows rods, when infection is recurrent, or when empirical therapy has failed. Samples should be collected by sterile swab from the deep portion of a pustule or from a tissue biopsy. Surface swabs of ulcerated lesions often grow contaminants. The AVMA practice resources provide guidance on antimicrobial stewardship that informs culture decisions.

Diagnostic Approach to Scaling and Crusting

Scaling and crusting disorders require systematic evaluation. The differential includes primary seborrhea, ectoparasites such as Cheyletiella and lice, dermatophytosis, autoimmune disease, and nutritional deficiencies. Skin scrapings and coat brushing for ectoparasites should precede more invasive testing. Cheyletiella mites are surface dwellers and may be missed on superficial scrapings, a flea comb and examination of dander under the microscope improves detection.

The following table summarizes lesion patterns and their diagnostic priorities:

Deep skin scrapings are required for Demodex mites, which reside within hair follicles. The skin should be squeezed to express mites from the follicles, and the scraping should be continued until capillary bleeding is seen. A negative scraping does not exclude demodicosis in deep or nodular lesions, and biopsy may be necessary.

Documentation and Monitoring

Dermatologic findings must be documented systematically to allow objective assessment of treatment response. A body map with lesion distribution, a pruritus score, and serial photographs provide the most reliable monitoring. The pruritus Visual Analog Scale, where the owner marks a line from no pruritus to severe pruritus, is practical in clinical settings. Serial cytology documents resolution of secondary infection and guides the duration of antimicrobial therapy.

Recheck intervals depend on the condition. Bacterial pyoderma requires recheck at 2 to 3 weeks to confirm cytologic resolution. Food elimination trials require recheck at 8 to 12 weeks. Autoimmune disease managed with immunosuppressive therapy requires more frequent monitoring of clinical signs and adverse effects. The ICVA NAVLE candidate information emphasizes that examination questions test the ability to select appropriate diagnostics and interpret results in sequence, which mirrors the clinical reasoning process described here.

Documentation should note the specific diagnostic tests performed, the results, and the rationale for each step. This record supports continuity of care and provides the basis for referral when advanced diagnostics such as intradermal testing or allergen-specific immunotherapy are considered.

Recognized Complications and Early Detection

The most consequential failure in dermatologic diagnosis is the misinterpretation of secondary lesions as primary disease. Pyotraumatic dermatitis, epidermal collarettes, and post-inflammatory hyperpigmentation can obscure the underlying hypersensitivity, endocrinopathy, or ectoparasitism that initiated the process. Detect this early by re-examining the patient after the secondary infection or inflammation has been controlled, then reassessing whether the original lesion pattern persists.

Biopsy-site complications include hematoma formation, seroma development, and wound dehiscence, particularly at mobile sites such as the axilla or pinna. Early detection relies on owner-reported swelling or discharge within 48 hours and a scheduled recheck examination. Cytologic sampling of any discharging tract is mandatory, as suture reactions and deep bacterial or fungal infections produce similar gross appearances.

Systemic complications from diagnostic procedures are less common but more serious. Sedation-related hypotension or hypothermia can occur during prolonged biopsy collection, especially in geriatric or hypothyroid patients. Monitor vital parameters throughout the procedure and extend recovery observation for brachycephalic breeds. Adverse drug reactions to local anesthetics or premedicants should be anticipated, ask specifically about prior anesthetic events before the procedure.

Common Errors and Corrective Action

Students and early-career clinicians frequently overinterpret single diagnostic findings. A positive skin scraping for Demodex mites does not exclude concurrent allergic disease, and a negative scraping does not rule out sarcoptic mange, as mite burden varies with lesion chronicity and prior topical therapy. Corrective action is to treat the most likely differential first, then reassess, instead of pursuing exhaustive testing before any intervention.

A second recurring error is the collection of inadequate biopsy samples. Punch biopsies that are too small, taken from the center of an ulcerated lesion, or crushed with forceps yield nondiagnostic histopathology. The corrective action is to biopsy the edge of active lesions, include adjacent normal skin, and handle tissue with minimal trauma. Multiple sites should be sampled when lesions vary in appearance.

Misidentification of normal anatomic features as pathologic also occurs. The ventral abdominal nipples of male dogs, the prominent sebaceous glands of the chin and tail head, and the normal hyperpigmentation of interdigital skin are frequently mistaken for disease. Correlate the physical finding with the history and cytology before committing to a diagnostic plan.

Limitations of Current Evidence

The evidence base for many dermatologic diagnostics rests on referral populations and may not generalize to primary care caseloads. Sensitivity and specificity figures for allergen-specific IgE testing, for example, vary substantially between laboratories and assays, and positive results do not confirm clinical allergy. Expert opinion still differs on the role of food trials versus environmental allergen testing as the first-line investigation in nonseasonal pruritus.

The MSD Veterinary Manual presents species-specific guidance, but the clinician must recognize that much of this material derives from canine and feline studies, with extrapolation to other species. Equine and bovine dermatology in particular have fewer controlled diagnostic studies, and treatment responses are often inferred from small case series.

Dermatophyte culture interpretation remains contested. Colony morphology alone is insufficient for species identification, and the significance of a positive culture in an asymptomatic carrier must be weighed against clinical signs. The World Organization for Animal Health terrestrial animal health standards provide guidance on reportable dermatologic conditions, but the clinician should verify local reporting requirements, as these vary by jurisdiction.

Referral and Reporting Thresholds

Referral to a veterinary dermatologist is warranted when a definitive diagnosis has not been reached after a systematic workup, when lesions progress despite appropriate therapy, or when the diagnostic plan requires procedures beyond the practice's capacity, such as advanced imaging or specialised allergy testing. Cases of suspected autoimmune disease, where biopsy interpretation is nuanced and immunosuppressive therapy carries significant risk, benefit from specialist confirmation before treatment begins.

Laboratory involvement is indicated when histopathology is required, when cytologic findings suggest unusual organizms, or when fungal culture and susceptibility testing will guide therapy. The AVMA practice resources offer guidance on professional conduct and referral communication, and the ICVA NAVLE candidate information outlines the examination domains that include dermatologic diagnosis and case management.

Regulatory reporting applies to suspected zoonotic disease, reportable foreign animal diseases, and conditions with trade implications. Suspicion of dermatophytosis in a multi-animal facility, sarcoptic mange in a shelter, or vesicular disease in livestock should trigger appropriate public health or regulatory notification. When in doubt, contact the relevant authority before proceeding, as delayed reporting can have broader consequences than the individual case.

Frequently Asked Questions

How do I prioritize dermatologic testing when the owner has a limited budget?

Start with the tests that most directly change your diagnostic plan. Cytology of lesional skin, impression smears, and ear swabs are inexpensive and provide immediate information about bacterial, fungal, and parasitic populations. Skin scrapings should follow when ectoparasites are plausible. If these are unrewarding, a therapeutic trial with a labelled ectoparasiticide may be more cost-effective than advanced imaging or allergy testing. Reserve biopsy and culture for cases that fail initial therapy or show progressive disease. Communicate clearly that skipping histopathology may delay a definitive diagnosis and increase long-term costs. The ICVA NAVLE candidate information emphasizes cost-conscious diagnostic reasoning as a core competency.

What is the minimum equipment needed to perform adequate diagnostic dermatology in general practice?

A microscope with oil immersion, glass slides, coverslips, scalpel blades, and a dental spatula or similar instrument for scrapings cover most needs. Diff-Quik stain, sterile saline, and mineral oil are sufficient for cytology and ectoparasite preparation. Acetate tape for adhesive preparations and a trichogram require no additional equipment. A 6 mm or 8 mm biopsy punch, forceps, and suture material allow sampling of most lesions. Dermatophyte culture medium can be purchased as ready-made plates. Practices without in-house culture capability can submit samples to commercial laboratories. The AVMA practice resources provide guidance on clinic laboratory standards and quality assurance.

How does the diagnostic approach differ between small animals and large animals?

Sample collection techniques are similar, but lesion distribution and differential priorities shift. In cattle and horses, dermatophytosis, ectoparasites, and bacterial folliculitis dominate, and herd-level factors such as housing, nutrition, and biosecurity influence interpretation. Deep skin scrapings may require more restraint and sedation in large animals. Biopsy site selection matters more when lesions are large or chronic, and healing times differ across species. Regional reporting requirements for certain nodular or ulcerative conditions vary, so consult the WOAH terrestrial animal health standards when a foreign animal disease is suspected. Always confirm that sampling equipment and fixation volumes are appropriate for the species.

What should I record in the medical record for a dermatologic case?

Record lesion distribution using a body map or standardized terminology, lesion morphology, and a numerical or descriptive scale for pruritus and erythema. Document which diagnostic tests were performed, the sites sampled, and the results. Note prior treatments, including drug, dose, duration, and owner-reported response. Photographs are valuable for tracking progression and should be stored with the record. Record client communication about prognosis, expected duration of therapy, and financial estimates. The MSD Veterinary Manual advises that dermatologic records support both clinical continuity and medicolegal defense when complications arise.

How do I explain the value of biopsy to a client who sees it as an unnecessary procedure?

Explain that biopsy is the diagnostic test that distinguishes between conditions that look identical on the surface, such as autoimmune disease, neoplasia, and deep infection. Describe the procedure as a minor surgical sampling that provides a definitive tissue diagnosis. Emphasize that treatment directed at the wrong disease is costly and may delay effective therapy. Mention that results take several days and that a single biopsy may not be representative, so multiple samples are often needed. The AAVMC veterinary education resources highlight that client communication about procedural value is a core clinical skill taught throughout the curriculum.

When should I refer a dermatology case instead of continue working it up in general practice?

Refer when the diagnostic plan exceeds your equipment, when a condition fails to respond to appropriate therapy, or when the differential list includes diseases requiring specialised testing such as immunofluorescence, advanced imaging, or complex allergy workup. Refer early for suspected autoimmune disease, progressive neoplasia, or conditions with zoonotic potential that you cannot confidently manage. If a foreign animal disease is possible, contact the appropriate regulatory authority before referral. The ICVA NAVLE candidate information lists recognition of referral thresholds as a required competency for entry-level practice. Document the reason for referral and provide the receiving clinician with cytology, biopsy, and treatment history.

Related Clinical & Scientific Guides

• Developing a Study Schedule for NAVLE Diagnostic Reasoning
• Veterinary Physiology Concepts Frequently Tested on the NAVLE
• NAVLE Clinical Rotation Preparation: What to Review Before Each Service

References and Further Reading

• ICVA NAVLE Candidate Information. ICVA.
• AAVMC Veterinary Education Resources. AAVMC.
• MSD Veterinary Manual, Professional Edition. MSD Veterinary Manual.
• American Veterinary Medical Association Practice Resources. American Veterinary Medical Association.
• WOAH Terrestrial Animal Health Code. WOAH.

Related Articles

• NAVLE Microbiology: High-Yield Bacteria and Fungi
• High-Yield Anatomy Review for the NAVLE: Canine and Feline Focus
• Veterinary Anatomy High-Yield Topics for the NAVLE
• Veterinary Microbiology High-Yield Topics for the NAVLE
• Veterinary Parasitology for the NAVLE: High-Yield Parasites

This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.