Induction of feline flea allergy dermatitis and the incidence and histopathological characteristics of concurrent indolent lip ulcers

The objectives of this study were to characterize the role of intermittent vs. continual flea exposure in the development of flea allergy dermatitis ( FAD) in cats, assess the accuracy of intradermal skin testing (IDST) and in vitro testing, and document the incidence and histopathological features o f indolent lip ulcers. Ten flea-naive cats were divided into two groups. On e group received intermittent flea exposure for 120 days. Thereafter, both groups of cats received continuous flea exposure for 120 days. In vitro tes ting for flea salivary antibody and IDST utilizing both whole flea antigen and flea salivary antigen were performed. Eight of 10 cats developed clinic al signs of FAD within 3 months and five of these eight cats developed lip ulcers which where characterized histopathologically by ulceration with pre dominantly neutrophilic inflammation and surface bacterial colonization. Th ere was no association between the presence or absence of clinical signs an d positive IDST or in vitro results, and no difference in the development o f clinical signs was noted between the two groups of cats.