An open label clinical trial to evaluate the utility of a hydrolysed fish and rice starch elimination diet for the diagnosis of adverse food reactions in dogs

Background The diagnosis of adverse food reaction ( AFR ) is based on an eight week elimination diet ( ED ) and is confirmed by relapse upon re‐challenge with the previously fed diet. Hydrolysed ED s are commonly used for this purpose. Objective To evaluate a commercially available hydrolysed fish protein and rice starch ED for the diagnosis of AFR . Animals Fifty nonseasonally pruritic dogs. Methods and materials Pruritus was assessed with a Visual Analog Scale, lesions with the Canine Atopic Dermatitis Lesions Index and quality of life with a validated questionnaire on days 0 and 56. Antimicrobial treatments were permitted during the first four weeks, and corticosteroids and oclacitinib during the first six weeks. Dogs showing at least 50% pruritus improvement were separately challenged with their prior diet, fish and rice. Results Thirty eight dogs completed the ED , four were dropped out due to worsening clinical signs, three to low palatability and five were lost to follow‐up. In 24 dogs, pruritus improved by >50% and 22 underwent dietary challenges. Of these, 15 reacted to their prior diets and were diagnosed with AFR , whereas seven did not relapse (and a diagnosis of AFR was considered to be doubtful). Five dogs reacted to fish and four to rice. Of the 14 dogs in which pruritus did not improve, some underwent a second ED and others were successfully treated for atopic dermatitis. Conclusion and clinical importance The hydrolysed fish and rice diet seemed to be a useful ED for the diagnosis of AFR , even in dogs allergic to fish or rice.