Adverse Food Reaction in a Dog

THE CASE

A 9-year-old intact male golden retriever was presented to his primary veterinarian for a year-long history of nonseasonal pruritus and recurrent pyoderma. Physical examination showed erythema, abrasions, and alopecia in the skin but was otherwise unremarkable. Blood work (ie, CBC, serum chemistry profile, total thyroxine) results were within normal limits.

Dietary History

A comprehensive nutritional evaluation¹ was pursued. The patient (71.7 lb [32.5 kg]) had a BCS of 5/9. The nutritional history noted the patient was eating an adult canine maintenance diet. After ruling out flea allergy, the veterinarian suspected food allergy and sent a serum sample for ELISA antibody testing. Rice, soy, and corn were identified as potential antigens.

Treatment Plan

The nutritional history uncovered potential sources of food allergens, prompting the veterinarian to change the current diet to one based on ingredients to which the patient had no known prior exposure (ie, fish and potato). This recommendation resulted in good control of pruritus, and the patient was diagnosed with suspected adverse food reaction (AFR). The patient ate this diet for 6 years without further issues.

DIAGNOSIS:

ADVERSE FOOD REACTION

Follow Up

After 6 years, the dog was presented for acute vomiting and diarrhea. He was hospitalized and underwent supportive care. He was presumptively diagnosed with pancreatitis based on clinical signs and altered specific canine pancreatic lipase (cPLI) of 415 µg/L (range, 0-200 µg/L). His current fish and potato diet provided 35% fat calories; to prevent pancreatitis recurrence, the veterinarian changed the dog’s diet to a weight-loss formula providing 20% fat calories and with main ingredients of wheat, chicken, and turkey. The patient recovered from the presumptive pancreatitis episode, but his skin signs and pruritus returned 2 months later.

After consultation with a dermatologist, the diet was changed to a hydrolyzed protein diet (based on chicken liver; 30% fat calories) to address the pruritus. The patient’s pruritus, however, did not decrease, and there was a recurrence of pancreatitis. Hydrolyzed diets are formulated to reduce the allergenicity of the protein source, but they do not completely eliminate it. Thus, a small percentage of patients intolerant to the original intact protein can also react to the hydrolyzate, which could have occurred in this case. The patient was offered a home-cooked diet based only on horsemeat and potato (no other ingredients or supplements), which provided 17% fat calories. Both his skin and GI signs resolved.

Nutritional Consultation

A nutritional consultation was conducted to find a long-term dietary plan. The owners were willing to home cook if necessary but preferred a commercial diet. Thus, after a careful diet history, the goal was to use a veterinary elimination diet that was not chicken based (because the patient had been exposed to chicken and the hydrolyzed chicken diet had not managed the pruritus) and had <30% fat calories. Two options were identified, one based on hydrolyzed soy protein (22% fat calories) and one based on duck and tapioca (24% fat calories). The owners elected the duck-based diet. After >1 year of follow up, the patient had no recurrence of skin or intestinal disease and his cPLI remained within limits.

Parting Thought

This case underlines the importance of a good nutritional evaluation, especially a careful and accurate diet history, in the diagnosis and successful long-term management of suspected AFR.

ASK YOURSELF...

Diet in Disease is a series developed by the World Small Animal Veterinary Association (WSAVA), the Academy of Veterinary Nutrition Technicians, and Clinician’s Brief.

AFR = adverse food reaction, CPLI = canine pancreatic lipase