The occurrence of fibromuscular dysplasia in the arteries of domestic turkeys.

Fibromuscular dysplasia (FMD) was found in 24 of 31 turkeys studied. This is the first species other than man in which FMD has been reported. FMD in turkeys simulates lesions variously known as fibromuscular dysplasia, fibromuscular hyperplasia, and medial hyperplasia in man. It occurred in turkeys from 8 weeks to 1 year of age and was evenly distributed between the sexes (11 males, 13 females). FMD in turkeys is a disease of arterioles and small arteries 44 mu to 666 mu in diameter. A lesion of more than 2.6 mm in length (in an artery 0.1 mm in diameter) was encountered. An adherent thrombus over 670 mu long was seen attached to an FMD lesion. Angiopathy appears to be basic to the pathogenesis of FMD and is characterized by endothelial hyperplasia, smooth-muscle vacuolization, and patchy necrosis of the media.