Pasture-associated seasonal respiratory disease in two horses

Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Veterinary Field Station, Roslin, Midlothian.

Two horses on separate farms developed severe obstructive pulmonary disease in successive years during the early summer months. In both cases clinical remission of the respiratory distress was achieved by moving the animals to different environments. The suggested aetiology for this outdoor chronic respiratory disease is a pulmonary allergy to pollen. Both animals were also shown to suffer from classical chronic obstructive pulmonary disease, i.e., obstructive pulmonary disease in the presence of hay and, or, straw.