Neurologic Case Shows Difficulty of Rule-Outs

A 24-year-old pleasure mare in Brunswick, Ga., has been diagnosed with concurrent infections of equine protozoal myeloencephalitis (EPM) and equine herpesvirus type-1 (EHV-1). Both can cause neurologic disease.

This case highlights the complexity of pinpointing neurologic illnesses, which can range from Eastern equine encephalitis to West Nile virus. With multiple infections, which is causing the problems and what should you treat?

Constance Hatchard, DVM, of Cheek to Cheek Hospital for Animals in Brunswick, referred "Louie" to Equine Associates in Hawkinsville, Ga., on Jan. 19, after the mare became ataxic (uncoordinated) and showed muscle fasciculations (twitching). Louie continually circled to the right, held her tongue out the side of her mouth, pursed her lips, and had proprioceptive deficits (she didn't know where her feet were). She was depressed, wouldn't eat grain, and would only eat a little hay.

Serum tests showed high EHV-1 antibody titers (indicating active infection). Serum and cerebrospinal fluid tests showed she was also positive for EPM. Louie responded to anti-inflammatory treatment and veterinarians prescribed Marquis for her EPM. She has returned home and is recuperating.

Hatchard thinks EPM is causing the signs, because "the neurologic signs seen with herpes are not being seen in Louie--she hasn't had urinary problems or fecal incontinence," and the signs are more characteristic of EPM.

Hatchard says, "Early detection and treatment means a better prognosis. Vaccines are never 100%, but it's important to have a good vaccine protocol and to vaccinate at least twice yearly for the respiratory and abortive forms of EHV." More information:

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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