Herpesvirus myeloencephalopathy in horses: 11 cases (1982-1996).

This research article focuses on understanding the results of Cerebrospinal Fluid (CSF) analysis in horses diagnosed with equid herpesvirus myeloencephalopathy (EHM) and whether these results can potentially predict the outcome of the disease.

Study Methodology

• The study relies on a retrospective review of medical records of 11 horses diagnosed with EHM from February 1982 to March 1996 at a veterinary teaching hospital.
• The factors taken into account included the age of the horses, the time of year of admission, fever presence before admission, stable exposure to other neurologically symptomatic horses, and observable clinical symptoms like hind limb ataxia and paresis, and cranial nerve deficits.
• CSF samples were collected from 10 horses out of 11 on the day of admission and analyzed for protein concentration, nucleated cell count, and Red Blood Cell (RBC) counts.

Results and Findings

• Most horses in the study were young (≤ 4 years old) and were admitted during the winter months (January to March). Fever before admission was noted in six horses, however no horse showed fever on the day of admission.
• Acute onset of hind limb ataxia and paresis was a common symptom in all horses. Five horses had been exposed to others with neurological disease, and three had cranial nerve deficits.
• In the day of admission CSF samples, high protein concentration was observed in eight horses, and eight had a normal nucleated cell count.
• No significant difference in CSF analysis parameters (Protein concentration, Nucleated cell and RBC counts) between surviving and euthanized horses was found. The study resulted in six euthanized horses and five survivors.

Conclusions and Implications

• The study concluded that CSF analysis, although showing common features in EHM horses like high protein concentration and normal or slightly high nucleated cell count, did not associate with the disease outcome.
• It was noted that horses becoming recumbent or unable to stand up during their EHM course had a poor survival prognosis.
• These findings suggest that while CSF analysis can aid in diagnosing EHM, it’s not a reliable tool to predict the outcome. Additional research is needed for prognostic tools in EHM treatment management.