COMMINUTED FRACTURE OF RIGHT TARSAL BONES WITH OLD CALLUS FORMATION IN A SLAUGHTERED PIG

Abstract

An enlarged and hard right hind limb of a condemned lame pig from a local slaughterhouse was submitted to National Chung Hsing University for pathological examination on 29 May 2015. Gross examination revealed brush burn and skin abscess. The radiography of the affected foot showed enlarged hock joint, collapsed tarsal joint with bony proliferation, and a soft tissue mass extending from the lateral to the tarsal bones. After the sample was split between the third and fourth metatarsal bone longitudinally, the calcaneus, talus, and the fourth tarsal bone were shown to be broken and damaged. Histopathological findings were as follows. First, the fractured bones showed the formation of callus and multiple small bone fragments were found. Second, osteoclasts and osteogenesis with bone remodeling were discovered at the edge of the bone fragments. Third, the skin abscess showed well-encapsulated clumps of bacteria and cellular debris. Trueperella pyogenes was identified from skin abscess and bone marrow. We speculate that the neglected fractures might have been related to crush injury inflicted by a sow or possible damage caused by the floor of the crate. This case highlights the importance of maintaining a high standard of animal welfare and once a lesion has occurred in food-producing animals, medication or elimination should be considered to avoid the long-term suffering of the animals.