Page 739 - Cote clinical veterinary advisor dogs and cats 4th

Food Allergy, Gastrointestinal 347

PROGNOSIS & OUTCOME a novel-protein home-cooked diet may be • Technicians have an important role in
required to see improvement. informing/educating clients on the feeding
VetBooks.ir offending foods. more common than dietary triggers in dogs during the elimination diet trial. Many Diseases and Disorders
changes and need for strict food control
• Considering that environmental triggers are
The prognosis is excellent with avoidance of
owners do not understand that “just one
with allergy, it is important to inform the
PEARLS & CONSIDERATIONS
owner that approximately 70%-80% of dogs
do not show appreciable reduction in pruritus treat” may invalidate the entire process, and
hearing this reinforced by the technician can
Comments during the food trial. Doing so may help be extremely valuable.
• The first step when dealing with any sus- avoid owner frustration and ensure better
pected CAFR is to make sure other causes of compliance. SUGGESTED READING
pruritus such as bacterial and yeast infection Miller WH Jr, et al: Muller & Kirk’s Small animal
and ectoparasites have been ruled out. Technician Tips dermatology, ed 7, St. Louis, 2013, Saunders, pp
• In some cases, a single elimination trial • Label the patient’s file in a readily identifi- 397-405.
may be insufficient, and a second elimina- able manner so that inappropriate treats AUTHOR: Andrew Lowe, DVM, MSc, DACVD
tion trial using an alternative prescription or diets are not fed if the patient is in EDITOR: Manon Paradis, DMV, MVSc, DACVD
novel protein or hydrolyzed protein diet or hospital.

Food Allergy, Gastrointestinal Client Education
Sheet

BASIC INFORMATION mucosal barrier, defective oral tolerance, or • Patient factors (e.g., compromised digestive
increased mucosal permeability function, defective oral tolerance, increased
Definition • Dermatologic: dermatologic food allergy mucosal permeability) play a role in inciting
Food allergy and food intolerance are repeatable (p. 345), atopic dermatitis (p. 91) an inappropriate immune response to an
adverse reactions to specific dietary components Clinical Presentation innocuous food.
that respond to exclusion of the causative agent.
Food allergy is immune mediated, whereas food HISTORY, CHIEF COMPLAINT DIAGNOSIS
intolerance is not. • Signs can include vomiting, weight loss,
intermittent abdominal pain, soft feces, Diagnostic Overview
Synonyms diarrhea (often predominantly large bowel), Diagnosis is based on a positive response
Dietary/food hypersensitivity, food-responsive borborygmus, flatulence, increased frequency to an elimination food trial. An accurate
enteropathy/diarrhea, adverse reaction to food of defecation (>3 times/day), perianal pru- diagnosis requires 1) proper elimination diet
ritus, and recurrent anal sacculitis. selection of a hydrolyzed protein diet or a
Epidemiology • Concurrent pruritus and cutaneous signs diet that is truly novel to that patient (com-
SPECIES, AGE, SEX raise index of suspicion. plete dietary history to ensure all ingredients
• Dogs and cats: no sex predisposition • The allergen(s) typically has/have been ingested previously ingested are eliminated during the
• Wide age range but tends to occur in for months to years before signs develop. trial); 2) strict dietary compliance during
younger animals (median, ≈3 years in dogs; • Signs may be intermittent due to factors the trial; and 3) no concurrent confounding
onset of signs at < 1 year in 33%-51% of such as frequency and amount of allergen(s) factors (e.g., antibiotics, glucocorticoids).
dogs) consumed and allergic threshold. For stable animals with chronic GI signs,
diet trial is often warranted before under-
GENETICS, BREED PREDISPOSITION PHYSICAL EXAM FINDINGS taking more invasive tests such as intestinal
• Any breed, but German shepherd, Labrador • Systemic: thin body condition, weight loss, biopsy.
retriever, Wheaten terrier, and Shar-pei are lethargy
frequently cited. • GI specific (see History above): patients often Differential Diagnosis
• Genetic predisposition can play a role in have a lower canine chronic enteropathy • Any primary disorder of the GI tract (e.g.,
development of food allergy. clinical activity index (CCECAI). parasitism, exocrine pancreatic insufficiency,
○ Irish setters may develop a familial gluten- • Skin: pruritus (face, neck, ears, ventral trunk, protein-losing enteropathy, antibiotic-
sensitive enteropathy. feet, perianal), otitis externa, urticaria, or responsive enteropathy, steroid-responsive
angioedema; in cats, self-inflicted alopecia enteropathy, inflammatory bowel disease,
RISK FACTORS or miliary dermatitis may be observed. GI lymphoma, other infiltrative disease)
• Increased intestinal permeability (e.g., • Extraintestinal disorders manifesting with GI
intestinal inflammation) Etiology and Pathophysiology signs (e.g., hypoadrenocorticism, hyperthy-
• Immunoglobulin A (IgA) deficiency and • Mechanisms unknown but genetic (e.g., roidism, liver, pancreatic disease)
other immune dysregulations (speculative) immune dysregulation) and environmental
• Allergic disease (e.g., atopic dermatitis) (e.g., intestinal microbiota) factors are Initial Database
suspected to play a role. • Dietary history
GEOGRAPHY AND SEASONALITY • Antigen is typically a protein or glycoprotein ○ Thoroughly evaluate the diet, including
Usually nonseasonal because the provocative of sufficient size to induce an immune reac- regular food, treats, human foods and
antigen(s) is part of the normal diet tion (in humans, typically 10-70 kD). scraps, flavored medications, foods used
• Most common antigens incriminated include to hide medication, supplements, and
ASSOCIATED DISORDERS beef, dairy, chicken, egg, wheat, lamb, and anything else ingested; read all ingredient
• Gastrointestinal (GI): any disorder leading soy (dogs); beef, dairy, fish, lamb, chicken, labels.
to decreased protein digestibility, defective and barley/wheat (cats). • CBC: often unremarkable

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