Mythbuster Monday: Senior Horses Should Be Vaccinated the Same as Younger Horses
On Mythbuster Monday, we tackle a variety of equestrian myths to either bust or confirm. Today’s discussion: Should senior horses be vaccinated the same as younger horses?
It’s Mythbuster Monday, where Horse Nation dives into different equestrian myths and provides research-based evidence to either bust or confirm those myths. Today’s topic: Should senior horses be vaccinated the same as younger horses? Is there a different time interval to vaccinate? Are some vaccines riskier than others? Read further to find out!
Myth: Senior horses should be vaccinated the same as younger horses
Myth or Fact: Myth
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Vaccination is recommended for all horses. When considering vaccination for your horse, it’s important to understand that each horse’s immune system is different and will respond to the vaccination differently. Not every horse will obtain the same level of protection and some may not be protected as long as others. Knowing your horse will allows you to decide whether an annual or semi-annual vaccination schedule will be more effective.
However, does the regimen change for senior horses?
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According to the Veterinary Medical Center of Easton, there are age related changes made to a horse’s immune system as he gets older. Senior horses are less able to resist infection — and the antibodies that immunity is built from. This makes it more likely that as horses age, they won’t respond well to vaccination. Chronic disease, age-associated inflammation, stress and nutritional status are all reasons senior horses become less responsive to or end up ill from vaccinations. Ultimately, this can lead to increased incidence of disease for vaccinated senior horses.
Studies have shown that vaccination in older horses is less robust than vaccination in younger horses. Vaccinations are only competent if the horse has a strong immune system. Therefore, senior horses with a more compromised immune system should not be vaccinated as often as younger horses in the barn.
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The University of Kentucky Ag Equine Programs did a study on 33 senior horses. The study administered different vaccines to the older horses to observe differences. The control group was given saline while other horses were administered different vaccines. Results showed there was no significant difference between horses in the control group and horses who were administered the influenza vaccine. However, there were differences in immune response noticed between the Herpes and West Nile vaccines. The results suggested that geriatric horses should be kept on a vaccine schedule with two boosters per year to obtain optimal immunity to the respective diseases.
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Miamitown Equine Veterinary Services posted that as horses age, their immune system becomes less effective. As long as horses are around dirt, they can contract tetanus, and as long as mosquitos are around, Eastern Equine Encephalitis, Western Equine Encephalitis, and West Nile can be contracted. This leads Miamitown Equine Veterinarian Services to recommend geriatric horses be immunized at least once a year, but they state because of the compromised immune systems, it is more effective if you keep the older horses on a biannual vaccine schedule.
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Purina Mills also discussed the vaccination schedule of older horses. They stated that as horses age, their immune system gets weaker. With this comes the added risk of vaccinating an older horse that is unable to handle creating antibodies to the disease. This may cause the horse to attempt to fight off the vaccine contents. On another note, the horse may not be able to create the same type of immunity to the vaccine as a younger horse. This requires the dose to be administered twice in a short period of time.
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After diving into the research, the consensus is that senior horses require different vaccination protocols than younger horses. It may be that some senior horses need vaccinated less while others need vaccinated more that a younger horse. Ultimately, it’s up to the owner and veterinarian to decide the best course of action to prevent disease in the individual horse. So, Horse Nation, vaccinate your senior horses according to their pre-existing conditions — not necessarily on the same annual schedule of the younger horses.
Do you have an equine myth you’d like us to tackle? If so, send it our way! Email your suggestions to [email protected]. Put Mythbuster Monday in your subject line.
