Grewar, John DuncanAllen, J.G.Guthrie, Alan John2010-02-192010-02-192009-12Grewar, JD, Allen, JG & Guthrie, AJ 2009, 'Annual ryegrass toxicity in thoroughbred horses in Ceres in the Western Cape Province, South Africa', Journal of the South African Veterinary Association, vol. 80, no. 4, pp. 220-223. [http://www.journals.co.za/ej/ejour_savet.html]0038-28097006535470J-6375-20130000-0001-7729-9918http://hdl.handle.net/2263/13128An 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.enSouth African Veterinary AssociationAnnual ryegrass toxicityHorsesCorynetoxinsMagnesium sulphateThoroughbred horseRyegrasses -- South AfricaVeterinary toxicologyPoisoning in animalsLivestock poisoning plantsArticle