Monday, June 19, 2006
I recently returned from the ACVIM (American College of Veterinary Internal Medicine) meeting in Louisville Ky. One of the special aspects of this meeting are the research Abstracts. These are 15 min. presentations given back to back for several days. Each of these is a synopsis of an ongoing research project and allows us as clinicians the ability to obtain information that won't be published for almost two years. There was a great deal of information concerning EHV myeloencephalopathy
(Neurologic Rhinopneumonitis). This is the same virus that we routinely vaccinate against for viral abortion and respiratory disease. EHV (Equine Herpes Virus) has the ability , like all Herpes viruses, to move into nerve tissue and become dormant, only to show up again during times of stress( ie. horse shows, illness, when treated with steroids). It has also been determined as of late that there may be a mutated form of this virus that has a higher propensity for neural tissue. The virus has also been shown to infect horses for years or possibly for life and can be shed by carriers without any outward signs. Therefore the most likely source of infection on the farm is from "hidden" carriers already there. Detecting the carriers is virtually impossible to boot. Our best course for now is to vaccinate frequently with a good EHV 1&4 vaccine and watch for any clinical signs. If an outbreak occurs then it is advised that you not booster at that time as it can cause more of the neurologic cases ( I know that doesn't make sense but the data is pretty conclusive). Furthermore no horses should be allowed to leave the farm for at least 28 days. I have to say that we have seen more of these cases over the last few years so you should be on the look out for horses that show an incoordination in the hind limbs and call at once.