Postvaccinal pyogranulomas in cattle

Clinical History: The carcasses of seven 30-month-old female cows slaughtered in a local abattoir for meat production were totally condemned during meat inspection due to disseminated gross abnormalities. Gross Findings: On internal examination, several skeletal muscles (pectoralis superficialis and profundus, transversus abdominis, diaphragm, obliquus internus abdominis, and rectus abdominis) and random areas of the peritoneal cavity had multifocal to coalescing nodules (1-3 cm in diameter). The nodules were firmly adhered (fibrous adherences) to the adjacent tissues and surface of portions of the forestomach serosa and splenic capsule. On the cut surface of the nodules, there was a central accumulation of a friable and yellow exudate surrounded by a fibrous capsule. No external lesions were seen in any of the cows.