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Journal of the South African Veterinary Association

versão On-line ISSN 2224-9435
versão impressa ISSN 1019-9128

J. S. Afr. Vet. Assoc. vol.80 no.4 Pretoria  2009




Annual ryegrass toxicity in Thoroughbred horses in Ceres in the Western Cape province, South Africa



J D GrewarI; J G AllenII; A J GuthrieI

IEquine Research Centre, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110 South Africa
IIDepartment of Agriculture and Food, Western Australia, Locked Bag 4, Bentley Delivery Centre, WA, 6983, Australia




An outbreak of annual ryegrass toxicity occurred on a Thoroughbred stud in Ceres in the Western Cape Province of South Africa. This is the 1st report of annual ryegrass toxicity in horses in South Africa, although the condition has been reported in cattle and sheep populations in the past. Annual ryegrass toxicity is characterised by a variety of neurological signs including tremors, convulsions, recumbency and in many cases death. The description of the outbreak includes the history, clinical presentation and treatment protocol administered during the outbreak. Various epidemiological variables and their influence in the outbreak are also considered.

Keywords: annual ryegrass toxicity, horse, corynetoxins, neurological, magnesium sulphate



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Received: July 2009
Accepted: October: 2009



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