title: Experimentally induced toxicoinfectious botulism in horses and foals.
abstract: Four experiments were performed to elucidate the pathogenesis of toxicoinfectious botulism in horses and foals. Groups of horses and foals were inoculated with one of the following: (1) crude toxin of Clostridium botulinum, type B, given IV, (2) C botulinum spores, given IM, (3) C botulinum spores, given IM, in necrotic lesions, and (4) C botulinum spores, given orally with and without dexamethasone. Toxin of C botulinum in minute amounts is toxic to horses. Clostridium botulinum spores produced toxicosis only when necrotic lesions were present. When C botulinum spores were given orally, they were innocuous. Toxicosis occurred when dexamethasone and C botulinum spores were given orally to a foal with necrotic lesions. Corticosteroids appear to predispose foals to the disease. In the animals where C botulinum organisms infected necrotic lesions, the clinical signs and the lesions seen on necropsy were identical with those seen in spontaneously occurring toxicoinfectious botulism.
mesh_terms: D000818:Animals; D001906:Botulism / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000209:etiology* / Q000473:pathology; D006736:Horses; D007273:Injections, Intramuscular; D008168:Lung / Q000473:pathology; D008297:Male; D009132:Muscles / Q000473:pathology; D009333:Neck / Q000473:pathology