Evaluation of the intradermal allergy test in normal dogs.

In 45 normal dogs, serial dilutions of different allergens were injected intradermally to determine the skin threshold concentrations. For housedust, housedust mite (Dermatophagoides pteronyssinus) and human dandruff extracts these were found to be the same in the dog as in man, while those for animal dandruffs, pollens and fungi were 10 times higher in the dog. The term 'histamine reactive value' (RH) is introduced for the dog. The mean (+/-SD) was found to be 49.0 +/- 2.5 in normal dogs, using histamine diphosphate solutions of 0.01, 0.1 and 1 per cent.