In a 6-month-old pig carcass, a lesion affecting the muscles of the back and, partially, the subcutaneous fat was observed with yellowish coloration and hardened consistency.

The histopathological study showed an inflammatory lesion of the muscle tissue accompanied by necrosis, intense fibrosis and regeneration of muscle fibers: chronic multifocal necrotizing myositis. This lesion inveolved alse the subcutaneous adipose tissue and was compatible with a lesion associated with the injection of an irritating (medicamentous) product.

Altered-looking dorsal musculature.

The affected muscles are hardened and have a yellowish coloration.

Detail of the muscle lesion.

Focally, the lesion spreads to the subcutaneous adipose tissue.