Just like cattle, ranch horses need properly timed and properly chosen vaccines.
Matt Randall, DVM, at Collier Equine, in Waller, TX, says that when ranchers ask which diseases they should vaccinate horses for, the main criteria is exposure risk. Some horses never leave the ranch and are never exposed to strange horses. This greatly reduces risk for contagious diseases that are spread from horse to horse like influenza or herpes viruses.
There are other diseases, however, which are caused by pathogens in the environment such as tetanus; spread by mosquitoes, such as West Nile virus and eastern/western equine encephalitis (EEE or WEE, respectively); other insects, such as the Potomac Horse Fever; or other animals such as rabies or leptospirosis.
Every horse, including ranch horses, should be vaccinated annually with what the American Association of Equine Practitioners calls the core vaccines: tetanus, EEE/WEE, West Nile, and rabies.
“Horse owners often ask why they should vaccinate against rabies, and I tell them that even though it’s one of the least likely diseases a horse would get, it’s also the most deadly, and will expose the people who handle that horse,” said Randall.
A horse with rabies may simply be dull, lame, colicky, or seem to be choking (unable to swallow). The owner might not suspect rabies and become exposed to the horse’s saliva while trying to care for, examine, or treat the horse.
“Human risk is one of the main reasons to vaccinate your horses for rabies,” he explained.
Risk-based diseases
While some vaccines are recommended for all horses, other vaccines would only be necessary in certain locales or situations.
If you take a horse off the ranch—to a trail ride, horse show or competition, to the neighbor’s place to help brand or gather cattle, or if taking a mare to be bred—you should vaccinate that horse ahead of time.
“If a horse comes into contact with other horses there is always risk, just like a kid going to day care or school, picking up colds or a snotty nose. They get exposed to something they have no immunity for,” Randall warned.
Equine herpesvirus (EHV-1), influenza, rhino, strangles, and leptospirosis are all diseases that may not be a threat to your horse unless he travels and comes into contact with other horses. EHV-1 can develop into the neurologic form of the disease and be fatal. Leptospirosis can cause moon blindness in horses, and abortions in pregnant mares.
Potomac horse fever is an equine disease that occurs in some regions but not others. Whether you vaccinate for this depends on where you live and if there have been horses getting this disease.
“The only time I’ve seen a horse get Potomac horse fever in Texas was at a big barrel race in Waco, and that horse came from Virginia—and just happened to get sick while it was at the barrel race,” said Randall.
There are many vaccines available, but this doesn’t mean your horse needs them all. There are some diseases your horses may never come into contact with, depending on where you live. In an area where anthrax is prevalent, you might want to vaccinate for anthrax, but for people living somewhere else this would never be important. Botulism is another example. There are regions where it’s important to vaccinate for botulism, and other areas where you’d never see it in horses.
It’s important to find out what the risks are in your area, to help you decide which vaccines to give, in addition to the core vaccines that every horse should have.
“If your horses are at low risk for certain diseases, there is no need to vaccinate for those,” explained Randall.
Timing and side effects
Foals and any adult horses that have never been vaccinated need a series of shots several weeks apart, to develop adequate immunity, and then an annual booster. Spring is the traditional time to give horses their annual booster vaccinations, but “spring” may be quite different in Texas than in Montana or North Dakota.
“Some vaccines just need an annual booster each spring, while others might require semi-annual vaccination, depending on risk,” Randall explained. If you live in a region where mosquitoes are active year ’round, for instance, you may need to vaccinate for mosquito-borne diseases again in late summer before the mosquitos become plentiful.
“Typically, we don’t see very many cases of West Nile or EEE/WEE until summer or early fall. Thus, if you vaccinate horses in the spring, they will probably be safe,” Randall explained. This may mean vaccinating in March or in May, depending on where you live.
“Vaccines are most effective when properly boostered, so there won’t be a lapse in immunity. If a properly vaccinated horse does get sick, some vaccine companies will stand behind their product and help with treatment costs,” he said.
Some horses develop temporary swelling/soreness at the injection site after vaccination and sometimes a mild fever for a day or two. “For the most part, equine vaccines are very safe, but you might not want to vaccinate your ranch horses the day before you need to work cattle or do a major roundup or cattle drive,” Randall advised.
Plan ahead and vaccinate several days or a few weeks before you need to ride them. — Heather Smith Thomas, WLJ correspondent
