BETA-GLUCURONIDASE AND TRYPSIN-INHIBITOR CAPACITY OF TRACHEAL LAVAGE FLUID AS INDICATORS OF SEASONAL AIRWAY IRRITATION IN THE HORSE

The health of the respiratory tracts of 19 horses was studied for 11 m onths. The horses were placed into 3 groups (healthy, periodically dis eased and continuously diseased) based on the measurements of blood ga ses, intrapleural pressure and on neutrophil content of tracheal mucus . Lysosomal enzymes (N-acetyl-beta-D-glucosam inidase and beta-glucuro nidase) and reflectors of the proteolytic system (plasmin, plasminogen , trypsin inhibitor capacity) were determined. beta-glucuronidase appe ared to be a good indicator of the presence of disease of the respirat ory system. High beta-glucuronidase values were seen in horses with el evated numbers of neutrophils, elevated arterial alveolar and intraple ural differences as well as in diseased horses during the stabling per iod. Trypsin inhibitor capacity seemed to be lower in the diseased res piratory system, probably due to the increased consumption of trypsin inhibitors.