Microbial Volatile Organic Compounds (MVOCs) - rare cause of occupational asthma in two veterinarians

Animal farming is associated with exposure to organic dust containing allergens, endotoxins, and alive microbial organisms. Microbial Volatile Organic Compounds (MVOCs) produced mainly by fungi and bacteria pollute the air and accumulate particularly in confined animal buildings, posing serious health hazards to workers, including veterinarians. The exposure can lead to rhinitis, chronic bronchitis, asthma, and chronic obstructive pulmonary disease (COPD). In a range of cross-sectional studies, wheeze and asthma were associated with exposure to swine, dairy cattle, horse, and sheep, but also to more specific exposures like manure. Occupational asthma has been reported in agricultural workers, including veterinarians. We report two cases of veterinarians who developed asthma in relation to prolonged and intense contact with sheep. No specific allergens could be found, MVOCs were considered as the causative agents.