Map shows the distribution of the two different parasites that cause equine protozoal myeloencephalitis. Courtesy of UC Davis
according to Nicola Pusterla, DrMedVet, PhD, DACVIM, professor of medicine and epidemiology at UC Davis, and lead researcher of the study. “This study returned positive results from more states than we originally thought,” Pusterla said.
Clinical signs
The central nervous system (CNS) infection affects both horses and ponies, and is often progressively debilitating because the parasites can affect anywhere from the front part of the cerebrum to the end of the spinal cord. Clinical signs depend on where the parasites reside in the CSN. Manifestations include gait abnormalities, incoordination, ataxia, spasticity, muscle atrophy, depression, behavioral changes and cranial nerve paralysis. “As the recognized geographic spread of N. hughesi infections expands, we are encouraging horse owners about the benefits of the
advanced tests available at UC Davis to more accurately diagnose the disease. Overall, we had not been satisfied with the standard testing available, so we have spent the past decade developing and successfully validating an improved diagnostic tool for EPM,” he said. UC Davis created the SarcoFluor and NeoFluor tests, which are immunofluorescent antibody tests for both of the known causative agents of EPM. These tests provide a quantitative indication of EPM infection and provide greater sensitivity and specificity than the Western immunoblot test on serum samples. UC Davis’ tests also reduce the necessity to obtain cerebrospinal fluid to screen for antibodies against the two protozoal agents. More than a decade ago, researchers at UC Davis were determined to create better testing for EPM. To that end, the School of Veterinary Medicine started devel-
oping a better diagnostic tool. “Since its discovery in horses, EPM has posed a significant diagnostic and therapeutic challenge,” said Claudia Sonder, DVM, director of the Center for Equine Health at UC Davis. “These new diagnostic tools are a product of the team science that changes clinical outcomes for horses treated at UC Davis. For the first time, veterinarians can associate probability of EPM infection with positive tests results, and can rule out both organisms known to cause EPM with negative tests. This advancement in diagnostic capability is welcomed by all faced with this complicated disease.” The SarcoFluor and NeoFluor tests are available through the laboratory services at the UC Davis Veterinary Medical Teaching Hospital. To learn how to use these tests and submit samples, contact VMTH laboratory services at 530-752VMTH or click here. MeV ModernEquineVet.com | Issue 1/2014
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