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Equine Protozoal Myeloencephalitis (view source)
Revision as of 12:01, 19 July 2010
, 12:01, 19 July 2010→Epidemiology
====Epidemiology====
====Epidemiology====
In endemic areas of the United States, around a quarter of referrals for equine neurological disease are attributed to EPM.(22,23 in Furr) According to the United States Department of Agriculture, the average incidence of the disease is 14 cases per 10,000 horses per year. However, the challenges of obtaining a definitive diagnosis may mean this figure is an underestimate (Furr). The disease has been identified in parts of Central and South America, southern Canada and across most of the USA.(Furr) EPM is noted occasionally in other countries, in horses that have been imported from the Americas.(28,29 in Furr). It is likely that these animals underwent transportation carrying a silent but persistent infection. There have been reports of EPM in horses that have not travelled to or from endemic regions(Furr), although cross-reacting Ags on the immunoblot test may explain this discrepancy(Furr).
The route of infection remains unconfirmed, (Pasq) but there is an increased risk associated with a young age (1-4yrs) (IVIS 3) and autumn months (24 in Furr). The reported age range for EPM cases is currently 2 months (34 in furr) to 24 years (35 in Furr). Thoroughbreds, Standardbreds and Quarterhorses are most commonly affected across the US and Canada (30 in Furr). This may relate to a breed predispostion or alternatively, managemental factors associated with these breeds(32 in Furr). Showing, racing (25 in Furr) and stress(25 in Furr) have been linked to a greater risk of clinical disease(IVIS 2). Case clustering may occur where all the risk factors are in operation, most cases appear in isolation (Furr).
Additonal risk factors for EPM: opossums seen on farm, woods on famr, (Furr), increased numbers of hroses, purchase dvs home-forwn grain, use of wood chips or shavings as bedding, presence of rats or mice, increased pop density
====Life Cycle====
====Life Cycle====