Clostridium botulinum type-C intoxication associated with consumption of processed alfalfa hay cubes in horses
Kinde, H.; Bettey, R.L.; Ardans, A.; Galey, F.D.; Daft, B.M.; Walker, R.L.; Eklund, M.W.; Byrd, J.W.
Journal of the American Veterinary Medical Association 199(6): 742-746
1991
ISSN/ISBN: 0003-1488 PMID: 1955364 Document Number: 373513
An episode of nervous system dysfunction was observed in horses on 17 premises in 4 counties of southern California. 38 horses were affected, and 31 of those died. The common clinical signs of disease in the affected horses were: increased appetite; anxious attitude; rhythmic, intermittent muscle tremors in the area of the triceps muscles; decreased palpebral tone; mydriasis; small hard faecal balls; and tendency to become sternally recumbent with the neck extended. The temporal distribution of cases on all 17 premises suggested a relationship between exposure to a common batch of alfalfa hay cubes and manifestations of similar clinical signs of disease in affected horses. 15 horses were submitted for PM examination. Botulism type-C1 toxin was detected in the feed, in intestinal contents of 1 horse, and in the liver of the aforementioned horse and another horse. Toxigenic strains of C. botulinum type-C were isolated from intestinal contents of 5 affected horses, one of which also contained type-C1 and type-C2 toxins. Seven of 10 horses treated with type-C antitoxin and plasma obtained from horses hyperimmunized with C. botulinum type-C toxoids survived.