Pneumabort is a lay term for a disease and vaccine related to Equine Herpes Virus -1, also called Rhino Virus. Of the 9 known Equine Herpes Viruses, two are of importance in domestic horses. These are Equine Herpes Virus -1 (EHV-1) and Equine Herpes Virus-4 (EHV-4). Both cause respiratory disease that can be either so mild there are no symptoms, or can have symptoms of fever, discharge from nostrils and eyes, and cough.

Since these are respiratory viruses, they spread in ways we are all familiar with…contact with a sick horse that is sneezing, coughing, or has runny nose or eyes. Horses in a barn or pen, or pasture animals sharing a fence-line can quickly infect each other. Shared water troughs and feed bins are another location for infection to spread.

However, since these are Herpes Viruses, there is also a more secret way they can spread. When a sick animal clears the original infection of EHV-1 but becomes a carrier. Think of your own human experience with Herpes Virus…a person who gets cold sores. They have no signs of a respiratory disease, but a cold sore develops on their lip. This comes from a Herpes Virus they had weeks, months, or years ago. It happens in horses too, but there is no cold sore. Instead, the horse may show signs of the original disease like a snotty nose, or there can be no symptoms at all. EHV-1 can also reactivate ONLY in the uterus or central nervous system (CNS).

In the horse with the reactivated virus, abortion can occur. If the virus spreads from a sick or reactivated horse to a pregnant horse abortion can occur.

This carrier stage can last for a few months, or for a horse’s whole life. So that makes it always a risk for pregnant mares, even in a closed herd (a closed herd is a group of animals that lives isolated with no new animals introduced and no animals leaving and returning from shows, races, or breeding farms). Protecting your pregnant horse from abortion caused by EHV-1 can only be accomplished by vaccinating with a vaccine specific for EHV-1---the Pneumabort vaccine!

By giving this vaccine at 5, 7, and 9 months of pregnancy you can protect your mare from abortion. You can purchase these vaccines through your veterinarian or through a reputable online source. Purchasing through your veterinarian is a great way to keep your veterinarian in the loop about how many mares you have bred and their respective due dates. In the Montrose area, we recommend Horsefly Creek Veterinary Services.

You can figure out when to give these vaccines using your mares’ breed date. For example, if she was bred on April 18th, then she will be due for her 5 month vaccination on September 18th, her 7 month on November 18th , and her 9 month on January 18th.