FLEA ALLERGY DERMATITIS IN DOGS DIAGNOSED BY INTRADERMAL SKIN-TESTS

Thirty-three dogs were categorised according to their clinical signs o f flea allergy dermatitis and reactivity to feeding fleas (Ctenocephal ides felis felis). A soluble extract of whole fleas (FS), fractions of this extract separated by chromatography, and a commercially availabl e flea antigen extract were used in intradermal skin tests (IDST) to e stablish the presence or absence of type I and type IV hypersensitivit y. The reactions were measured and the results were analysed using thr ee grading systems commonly reported in the literature. The results of the IDST for the groups of dogs varied according to the grading syste m used. FS, the most effective of the antigen preparations, identified 94 per cent of dogs which reacted to feeding fleas when a result was considered positive if the mean diameter of the wheal at the antigen i njection site exceeded the diameter of the wheal at the negative contr ol site by five mm at 15 and/or 30 minutes after injection.