HERPESVIRUS MYELOENCEPHALOPATHY IN HORSES - 11 CASES (1982-1996)

Objective-To determine results of CSF analysis in horses with equid he rpesvirus myeloencephalopathy (EHM) and to determine whether results o f CSF analysis were associated with outcome. Design-Retrospective stud y. Animals-11 horses. Procedure-Medical records of all horses admitted to the veterinary teaching hospital between February 1982 and March 1 996 in which EHM was diagnosed were reviewed. Results-7 horses were le ss than or equal to 4 years old; 8 were admitted during January, Febru ary, or March. Six horses were febrile prior to admission, but none wa s febrile on the day of admission. Five horses had been stabled with o ther horses that had clinical signs of neurologic disease. All horses had had an acute onset of hind limb ataxia and paresis. Cranial nerve deficits were detected in 3 horses. Cerebrospinal fluid samples were c ollected on the day of admission from 10 horses. Protein concentration was high in 8 horses; nucleated cell count was normal in 8. Protein c oncentration and nucleated cell and RBC counts were not significantly different between horses that survived and horses that were euthanatiz ed. Six horses were euthanatized, and 5 survived. All of the horses th at survived remained standing or were able to stand with minimal assis tance. Clinical Implications-High CSF protein concentration and normal or only slightly high CSF nucleated cell count are common in horses w ith EHM; however, results of CSF analysis were not associated with out come. Horses with EHM that become recumbent have a poor prognosis for survival.