Differential diagnoses for the suspected EHM case

It is the same with equine herpesvirus type 1 (EHV-1): any patient with sudden ataxia, weakness, micturition difficulties or ‘found recumbent – unable to rise’ should be at least briefly considered a horse with equine herpesvirus-associated myelopathy (EHM). An EHV-1 infection can rapidly spread within a herd resulting in multiple horses affected by EHM. The best outcome of an EHV-1 outbreak comes through early and aggressive mitigation. A ‘case 0’ or index case diagnosis can be challenging, but specific testing and risk factor analysis can help you to narrow down the diagnosis. Nasal swabs in combination with EDTA blood for PCR analysis will supply quick results, although there is a 24-hour turnaround time for most laboratories [1]. Consider the time of the year, breed and age to help you rule in or rule out EHM. It is more common to encounter EHM during the cooler time of the year and it more commonly develops in adult horses of the tall breeds, while it is less likely to have an index case in an Arabian horse, pony or young adolescent animal (<3years) ...