Gas Gangrene in Horses: Retrospective Study of 20 Cases in the Amazon Biome

This is the first study describes, through a retrospective analysis, the epidemiological and clini-copathological findings of gas gangrene in horses in the Amazon biome. The study includes 20animals with muscle and mobility injuries treated at proprieties in the Amazon biome from 2018 to 2024. The affected horses exhibited a sudden onset of severe lameness, swelling, and crepitus in the affected limb. The rapid progression of symptoms, including intense pain, fever, and toxemia, led to the clinical suspicion of gas gangrene. Immediate treatment was crucial, involving ag-gressive surgical debridement to remove necrotic tissue and high doses of broad-spectrum anti-biotics to combat the infection. Despite these efforts, the condition of the horses deteriorated rapidly due to the aggressive nature of the disease and the challenging environment of the Am-azon, which complicates timely veterinary intervention. The age range of the affected horses was from four months to 12 years, with a greater frequency in those over 12 months (80%, 16/20). Necropsy revealed histopathological lesions characterized by intense muscle necrosis, liquefac-tion, and gas formation, suggestive of Clostridium infection. The diagnosis was confirmed by multiplex PCR.