sometimes not at all. Meaning that many horses with mild cases will never be diagnosed at all. A Western blot test can be used to test blood serum for anti-bodies indicating exposure, however a positive serum result does not mean that the horse is infected with the disease. Because EPM can present itself like a number of other diseases it is necessary to use further tests to definitively diagnose. For most animals this means an analysis of the cerebral spinal fluid (CSF) which when abnormal will show in increased level of proteins and inflammation. (Fenger, 1996) The CSF can be extracted either from the Allanto-occipital space (where the head meets the neck) or from the Lumbo-sacral space (above the hindquarters.) However since the CSF flows in a caudal (towards the back) direction the Lumbo-sacral space is preferred as it will be more likely to show inflammation. Also important to consider is that testing the Allanto-occipital space requires that the horse be anesthetized and laid down, which can be dangerous in a horse that has neurological problems. (Levine, 1999)The University of Missouri-Columbia’s current recommendations for treatment include a course of oral anti-protozoal drugs combined with sulfa drugs for a minimum of 12-16 weeks, and the horse should remain on the medication for 4 weeks after neurological symptoms disappear. The relapse rate after treatment is about 40%, however the majority of those cases occur because treatment was discontinued after less than three months. (Fenger, 1996) The current medicine of choice is Sulfadiazine and Pyremethamine used together, they should be administered once a day orally on an empty stomach to achieve peak drug levels. (U. Missouri… 1999) About 10% of horses experience a ‘treatment crisis’ where the symptoms actually worsen while on the medication, this may be caused by the dying parasites and the resulting inflammation. Usually these horses respond to anti-i...
