Pulmonary vascular response of dogs with heartworm disease.

Heartworm diseases in dogs is an infectious disease that produces pulmonary hypertension. Dogs with the early vascular changes of heartworm disease, but without the clinical cardiopulmonary signs and pulmonary hypertension, were studied. Dogs with early heartworm were identified that had an exaggerated hypertensive response to hypoxia and to postaglandin F2alpha as compared to those of normal dogs. The pulmonary hypertensive response of dogs with spontaneous heartworm disease varied widely between individuals.