Establishment of clinical criteria for the diagnosis of adverse food reactions in dogs with atopic dermatitis.

Abstract

Diagnosis of canine adverse food reactions (AFRs) is based on vague criteria, such as '>50% improvement' during elimination diet trial (EDT) followed by 'deterioration' during provocation test (PT). The objective of the study was to use predefined criteria to evaluate response during EDT [i.e., Owner Global Assessment of Treatment Efficacy (OGATE) = good-to-excellent] and relapse during PT [i.e., Owner Global Assessment of Challenge Deterioration (OGACD) = moderate-to-severe and/or >100% increase of lesional (Canine Atopic Dermatitis Extent and Severity Index, 4th iteration, CADESI-04) and/or of pruritus (pruritus Visual Analog Scale, PVAS) scores]. Twenty-nine dogs with atopic dermatitis. An extensively hydrolysed diet was fed to all dogs followed, in seven of 11 nonresponders, by a second home-made novel-protein EDT. Dogs responding to either EDT were challenged with their previous diet. Thirteen (44.8%) dogs were diagnosed with AFRs: at the end of EDT, their OGATE was good (9 of 13; 69.2%) or excellent (four of 13; 30.8%), and both CADESI-04 (46.7%) and PVAS (71.1%) had decreased significantly; at the end of PT, OGACD was moderate or severe in 12 of 13 (92.3%) dogs, and both CADESI-04 (127.9%) and PVAS (181.8%) had increased significantly. Of the 16 dogs without AFRs, 6 (37.5%) responded to the commercial (n = 5) or home-made (n = 1) diet [OGATE = good (three of six) or excellent (three of six)], with significant concurrent reduction of CADESI-04 and nonsignificant reduction of PVAS, yet they did not relapse during PT. The proposed (predefined) criteria for the evaluation of response during EDT and deterioration during PT seem reliable and are easily applicable in clinical practice and research.