Unusual Gross Presentation of Sarcocystis-Like Pectoral Muscle Lymphoma Attributed to Marek's Disease in a Backyard Chicken

Abstract

Marekʼs disease–induced lymphomas of skeletal muscle are rarely reported in chickens. Three mixed-breed, adult backyard chickens, which belonged to a flock with a previous history of anorexia, depression, ruffled feathers, whitish diarrhea, weight loss and death, were submitted for postmortem examination and diagnostic testing. Grossly, 2 birds had moderate pectoral atrophy, whereas the remaining chicken had numerous white, rice-grain sized foci distributed throughout the pectoral musculature. Severe proventricular wall thickening was observed in all 3 chickens and moderate intestinal Ascaridia spp. parasitism was diagnosed in 2 of the birds. Microscopically, the peripheral nerves, cerebrum,..