Farmers follow their vet’s recommendations when it comes to vaccinating their horses

Horses may love apples, but it takes more than an apple a day to keep the vet away. Most farmers will agree that vaccines play a vital role in protecting their horses’ health. But, without state requirements, they tend to follow their vet’s recommendations. This means, veterinarian distributor reps should work closely with their customers to ensure they are well stocked with the right products at the right time of year.

Vaccine recommendations
There is no standard vaccination program for all horses, according to the American Association of Equine Practitioners (AAEP). Rather, every situation requires evaluation based on the following criteria:
• Risk of disease, including exposure, environmental and geographic factors, and age, breed, use and sex of the horse.
• Consequences of the disease (e.g., morbidity, zoonotic potential, etc.).
• Potential for adverse reactions to a vaccine.
• Cost of immunization vs. potential cost of the disease (e.g., opportunity for spread of disease, cost of treatment and/or loss of life).

And, while vaccinations help minimize the risk of certain infections, they cannot always prevent a disease.

The AAEP Infectious Disease Committee 2008 compiled a list of core-based vaccinations, as well as a list of risk-based vaccinations. Core vaccinations refer to those that protect horses from highly virulent or infectious diseases endemic to a particular region or posing a significant public health threat. They include tetanus, Eastern/Western Equine Encephalomyletis, West Nile Virus and rabies.
“These are just recommendations,” says Daniel Kenney, VMD, diplomate ACVIM. “Horse owners should discuss [their animals’ needs] with their veterinarians.” So, in areas where there is a prevalence of rabies, vaccination for this disease can be life saving. “If a horse is not vaccinated for rabies and encounters it, it could kill the animal. It’s almost always fatal,” he says.
Risk-based vaccinations generally vary from one region to the next, from population to population within an area, or between individual horses within a particular population, according to the AAEP. These include vaccines for anthrax, botulism, equine herpesvirus (rhinopneumonitis), equine viral arteritis, equine influenza, Potomac horse fever, rotaviral diarrhea and strangles.
As with diseases associated with core vaccines, clients typically have their horses vaccinated for risk-based diseases when their veterinarian recommends they do so. Veterinarians, in turn, adhere to manufacturer recommendations, says Kenney. For instance, “mares are vaccinated in the last month of pregnancy,” he says. “Then, the antibodies will get into their system and protect the baby horse in its first several months of life.”

Preventing spread of disease
Veterinarians may encounter noncompliance from time to time, but most practitioners are pleased that their clients adhere to vaccination schedules, notes Kenney. “There are no real safety issues associated with vaccines,” he points out. “Most adverse reactions are limited to local swelling. And, if clients are concerned that their horses are receiving too many vaccines, the veterinarian can space them out.” The important thing is that veterinarians keep their clients educated on the dangers of exposing one of their horses to disease.
Sometimes an infected horse can be stabilized if it contracts a mild form of a disease. In some cases, however, a disease can be detrimental to the farmer’s horses – and his or her livelihood. “Herpes is an interesting organism, and in horses it can cause various problems,” says Kenney. “Neurological herpes can cause inflammation of blood vessels, leading to problems with the blood supply to the central nervous system. The horses lose stability in their limbs, starting with the hind limbs. They also can experience brain cell damage, which leads to depression or a lack of response to their surroundings. However, in mild forms of the disease, the horse often can be stabilized,” he adds.
“Diseases can spread not only from one mammal to another, but from mammal to people as well,” Kenney continues. And, depending on the organism, a disease can spread very rapidly through a herd of horses, he notes. Influenza spreads particularly fast. “The owner may have to quarantine [ill] horses, and it is prudent for them to vaccinate horses new to the farm, especially for strangles,” he says.
In some cases, however, it is too late to vaccinate the horses. “If other horses on the farm have been exposed to a disease, it is not necessarily a good idea to vaccinate them at that point,” Kenney says, noting that they may be incubating the virus. The decision to vaccinate depends largely on the owner’s discretion, veterinarian counsel and the farm setup, he adds. “If the other horses are not located in close proximity to the ill horse, it may not be too late to vaccinate them,” he says.

For more information on equine vaccine recommendations, visit the American Association of Equine Practitioner’s Web site at www.aaep.org.