Basenji-Greyhound dog model of asthma: reactivity to Ascaris suum, citric acid, and methacholine.

Bronchial inhalation challenges to Ascaris suum, citric acid, and methacholine were performed in eight Basenji-Greyhound (BG) crossbreed dogs, five of which were reactive to Ascaris antigen aerosols (AAA). Responses to aerosol challenges were measured as changes in pulmonary resistance (RL) and dynamic compliance (Cdyn) and were compared to responses obtained in five mongrel dogs. Responses to methacholine and citric acid were similar in BG dogs whether Ascaris-sensitive or not, but BG dogs were clearly more reactive than mongrels to both types of nonspecific challenge. Methacholine responses were elicited at 10-30 times lower concentrations in BG dogs than in mongrels; 10% citric acid, which failed to elicit any response in mongrels, increased RL 5- to 10-fold in BG dogs. We conclude that the BG dog demonstrates nonspecific bronchial hyperreactivity, as in human asthma.