T. J. Barclay, DVM
“Doc, does my horse really need all those shots?” I wish I had a dime for every time I’ve heard those words! Routine vaccinations are one of the most basic aspects of general horse care, but are frequently misunderstood and misused. In this article I will discuss vaccination of adult horses (yearlings can also be included in this category). Vaccination of broodmares, foals, and weanlings will be covered in a later article.
The question of “What vaccines do horses need?” does not have a single answer. It depends on several things, such as age, environment, prior vaccination status, and what the horse does for a living. In order to simplify these considerations, vaccines can be divided into two groups: Core and Non-core. Core vaccines are those which all horses need “just because they’re horses”. These vaccines are for diseases that occur in all areas of the country and can be contracted by any horse regardless of age, environment, or activity. Non-core vaccines are for diseases that only occur under special circumstances. Below I will list both core and non-core vaccines recommended in the Texas Panhandle and how often they should be administered. For most vaccines, if a horse has never been vaccinated, they will require a series of two or three shots initially.
Core vaccinations include the following:
- Eastern and Western Equine Encephalitis – Given yearly in the spring – Commonly known as “sleeping sickness”, these diseases are caused by viruses that are spread by mosquitoes.
- West Nile Encephalitis – Given yearly in the spring –West Nile virus is also spread by mosquitoes and many horse owners in this area are all too familiar with this disease.
- Tetanus – Given yearly – Similar to the disease in humans, tetanus is usually contracted through penetrating wounds. If a horse sustains a laceration or puncture and has not had a tetanus vaccine within the last 6 months, a booster should be given immediately.
- Rabies – Given yearly – Although not required by law as in dogs and cats, rabies is important to protect the health of horses and their owners. Rabies is contagious to humans and if contracted, is always fatal.
Non-core vaccines and the conditions under which they should be given are as follows:
- Influenza – Given every 6 months – “Flu” is a highly contagious viral disease that causes fever, coughing, and nasal discharge. Any horse that is or will be in contact with other horses, such as at rodeos, shows, sales, boarding stables, or breeding farms should be vaccinated.
- Equine Herpes Virus – Given every 6 months – Rhinopneumonitis, commonly known as “Rhino”, causes symptoms similar to the flu virus and can also cause abortions in mares. Like flu, vaccination for EHV is needed in horses that are routinely exposed to other horses.
- Streptococcus equi – Given every 6 months – “Strangles” is a bacterial disease that causes abscess formation in the jaw and throatlatch area as well as respiratory disease. Vaccination should be considered in horses that are exposed to other horses. Vaccines for strangles typically have a lower success rate and a higher rate of side effects than other vaccines, but the benefits of vaccination often outweigh the risks.
- Equine Viral Arteritis – This virus causes abortion in mares, and fever, respiratory disease, and limb swelling in other horses. There are many things to consider when deciding whether or not to vaccinate for this disease. You should consult with your veterinarian to learn more.
Another decision that owners must make is whether to give vaccines themselves or to have their veterinarian give them. For owners who are comfortable with giving injections, this option is often more convenient. However, there are several benefits to having vaccinations performed by your veterinarian after a thorough physical examination. If your horse has a subtle problem, the doctor can often detect it before it becomes severe and give the proper treatment. Also, vaccination time is a perfect opportunity for your vet to get to know you and your horses, rather than meet for the first time in the middle of the night when you have an emergency.
For more information, the American Association of Equine Practitioners (AAEP) has recently published updated guidelines for vaccination of horses. These can be viewed at www.aaep.org/vaccination_guidelines.htm. Also, remember that your veterinarian is the most important source of information about vaccines and horse health in general. He or she can help you tailor a vaccination program to your situation, whether your herd is one horse or a hundred!
