Laryngeal chondropathy in a group of broodmares

Fourmiddle-aged (x= 11.5 years old) Thoroughbred mares from one broodfarm were examined over a 1-week period because of respiratory distress of acute onset. The mares began making abnormal respiratory noise 1 week prior to examination. Three of the mares had shown similar respiratory dyspnea during the fall. The mares maintained a good appetite and condition, and three were in early stages of pregnancy. They were pastured most of the time. The 4 mares had been imported from the USA (Kentucky) 5 years previously, and were members of a herd that consisted of 60 mares, their offspring and 6 stallions. The herd members were regularly vaccinated against rhinopneumonitis, influenza, rabies and encephalitis, and were regularly dewormed.