An open-label clinical trial to evaluate the efficacy of an elemental diet for the diagnosis of adverse food reactions in dogs

Background: The diagnosis of cutaneous adverse food reactions (CAFR) in dogs is dependent on a diet trial and provocative challenge.Hypothesis/Objectives: To evaluate the efficacy of an elemental diet for the diagnosis of CAFR in dogs.Animals: Sixty-two client-owned nonseasonally pruritic dogs.Materials and Methods: A prospective, uncontrolled, observational elimination diet trial study. Dogs were fed a commercially available elemental canine diet (Pro Plan Veterinary Diets EL Elemental Canine Formula, Nestle Purina PetCare Company) for up to eight weeks. Pruritus was assessed using a validated Visual Analog Scale (PVAS), lesions with the Canine Atopic Dermatitis and Severity Index, 4th iteration (CADESI-04) and gastrointestinal (GI) signs with a client questionnaire. All dogs were challenged with their previous diet for up to 14 days. Treats were added from Day (D)7 to D14.Results: Forty-five dogs completed the study. Eighteen (40%) of these were diagnosed with CAFR and 27 (60%) were diet-nonresponsive (NR). Dogs with CAFR flared on provocative challenges within 14 days. The smallest volume of previous diet that induced a CAFR flare was one teaspoon in two dogs (11.1%). The mean number of days leading to a provocation of clinical signs was 4.88 days. Gastrointestinal signs improved in both groups. Eight of the dogs with CAFR (44.4%) were subsequently maintained on the elemental diet alone.Conclusion and Clinical Relevance: Pro Plan Veterinary Diets EL Elemental Canine Formula is efficacious for the diagnosis of canine CAFR. One teaspoon of the offending diet may induce clinical signs in some dogs with CAFR.