Inflammation induced by subcutaneous turpentine inoculation of young American alligators (Alligator mississippiensis).

Turpentine-induced skin lesions in young American alligators (Alligator mississippiensis) kept at 25 C were used to study inflammatory response in a reptile. Skin harvested at intervals between 4 hours and 30 days after inoculations were done had no gross changes until days 24 to 26, when superficial skin necrosis was evident. Early responses of congestion and dermal edema (4 to 8 hours) were seen by light microscopy, and these were followed by necrosis and granulocyte migration (1 to 3 days). Later, there was predominance of monocytic cells, including vacuolated macrophages (7 to 30 days). Evident at 14 days and prominent by day 30 were central dermal zones of necrotic debris surrounded by orderly palisades of vacuolated multinucleated giant cells and capillary-laden immature fibrous connective tissue. Systemic illness or visceral lesions were not observed. Controls, given inoculations of sterile saline solution, had no gross or microscopic changes.