Did you know that horses receive more vaccinations on a more frequent basis than any other domesticated animal?
It’s true. And while there has been discussion regarding over-vaccination with dogs and cats, it seems to be a topic which is ignored in equine veterinary medicine. However, due to the apparent rise in adverse vaccine reactions, many horse owners are now rethinking vaccinations, as a whole.
For many years, the notion that “more is better” remained as the standard protocol in vaccinating horses. And while there’s no doubt vaccines can and do protect our animals from a number of serious infectious diseases, many holistic practitioners have discovered that over-vaccination is linked with a myriad of other diseases—especially those which affect the immune system.
It’s important that horse owners not only become educated on this issue, but also learn to strike a balance. It’s not that vaccines should be totally avoided—but the idea that “more is better” must be rethought if we are to preserve our horses’ health.
Science has shown that many vaccines protect animals for far longer than a year, which is the typical length of time until re-vaccination. Unfortunately, not all veterinarians are a.) aware of this or b.) willing to part with outdated protocols. Regardless of new data, many still go by the vaccine companies (often profit-driven) recommendations to vaccinate annually.
In some states, annual vaccinations are required by law, but in others, horse owners have the option to use serum antibody titers instead. However, it is often up to the owner to pursue this route, as many veterinarians may not.
Titer tests are done by using a blood sample. They measure the amount of specific antibodies for disease-causing agents (antigens) which develop from either being previously exposed to that disease or receiving a vaccine to protect against that disease.
Research has also shown that once a horse’s titer stabilizes (after vaccination or exposure to disease), it is likely to remain constant for a number of years. Titers can be tested every three years or as needed to find if immune memory has been established. If it has, re-vaccination is not necessary at that time. The key is to avoid vaccinating horses against diseases they are already protected from.
Positive titer tests are easy to interpret, but a negative test doesn’t necessarily mean the horse is unprotected. A decision must be made if vaccination is warranted under those circumstances. Additionally, a positive titer result is not likely to drop off unless the animal develops a medical problem such as cancer or receives high or prolonged doses of immunosuppressive drugs. In other words, once you have an acceptable titer result, you should not have to repeat the test or re-vaccinate for several years.
Titers are currently available for the following equine diseases: equine herpes virus (EHV-1, EHV-4), Potomac Horse Fever, Equine Encephalitis (EEE, WEE, VEE), Equine Viral Arteritis, Equine Influenza, Rabies, and West Nile.
If your horse is due for vaccinations, ask your veterinarian for titer testing instead of automatically re-vaccinating.