Respiratory disorders in Manitoba cattle farmers.

A group of 76 cattle farmers from southern Manitoba answered the National Heart, Lung, and Blood Institute questionnaire on respiratory symptoms and supplementary questions on farming and farming-related syndromes. Lung function was tested, serum was examined for precipitating antibodies, and skin testing with common allergens was performed. Analysis of the men's answers revealed a high prevalence of chronic respiratory symptoms among the farmers in all categories of smoking history, and the presence of these symptoms was significantly associated with a history of symptoms related to handling mouldy hay or grain; 51% of the men had chronic symptoms and 55% had symptoms related to crop handling. In seven farmers (9%) the symptoms related to crop handling suggested an attack of farmer's lung. One other farmer, with a history of illness after handling mouldy hay, had a reduced total lung capacity, and in 18 the ratio of the forced expiratory volume in the first second to the forced vital capacity was lower than predicted. Precipitating antibodies against Thermoactinomyces were absent in all farmers, but two farmers had antibodies against Aspergillus ruber. Immediate hypersensitivity was found in 16 (21%) of the farmers; sensitivity to Dermatophagoides farinae was commonest.