In all honestly I'm a mildly paranoid horse owner, likely because of the unending stream of horror stories about equine diseases, injuries, and ailments I'm exposed to working at a horse health magazine and website. While I'm resigned to the fact that my 16-year-old Thoroughbred can't live in a bubble to be safe from everything, I do rely on vaccinations to help protect him from some potentially deadly ailments he could face.


This spring, Dorado was vaccinated against Eastern and Western equine encephalitis, West Nile virus, tetanus, rabies, influenza, rhinopneumonitis, and botulism. He'll get a flu/rhino booster this fall.

Each spring and fall my veterinarian and I discuss which vaccines Dorado should have, but in most recent years past he's been inoculated for Eastern and Western equine encephalitis (EEE and WEE), West Nile virus (WNV), tetanus, rabies, influenza, rhinopneumonitis, and botulism. We generally choose not to vaccinate him strangles and he does not receive a Potomac horse fever vaccine because he's had the disease in the past.

Even though I'm pretty comfortable with how I go about vaccinating Dorado, I've heard several different theories from different owners on vaccinating older horses in the past few years. One owner told me that she's stopped vaccinating her senior horses because with all the vaccines they've had in the past, they surely have developed immunity to the diseases by now. Another owner, who vaccinates her own horses, says she's heard older horses have decreased immune systems, so they need to be vaccinated more frequently than younger horses.

Have I been over-or under-vaccinating Dorado? Should I change my approach to vaccinations as he ages? To ease my paranoia, I chatted with The Horse and regular contributor Stacey Oke, DVM, MSc, about the theories I've heard in regards to vaccinating older horses.

She very tactfully and reassuringly answered that, considering vaccines aren't overly expensive and all horses should have a physical exam each year, she highly recommends owners follow the American Association of Equine Practitioners' (AAEP) vaccination guidelines.

If you're concerned about an older horse's immunity status, Joseph Bertone, DVM, MS, Dipl. ACVIM, recommended in a previous article on that "owners of older horses have their veterinarians take and test a blood sample before vaccination and one month after vaccination to gauge the horse's reaction to vaccination by looking at antibody titer levels. If the veterinarian thinks antibody levels are too low, he or she might decide that an additional booster could benefit your horse."

So what have I learned from all this? I think I'll stick to my approach to choosing vaccinations. My veterinarian follows the AAEP guidelines, and I know he'd tell me if something needed to change with our current vaccine schedule.

Speaking of which, fall is just around the corner. Guess I better make an appointment to get those fall shots!

Which vaccines do your senior horses receive each year? How do you make those selections? Share your experiences below!