Page 25 - Canada Spring 2019

“It’s always a good idea to talk to your veterinarian about vaccination schedules for foals.”
The history of the mare is important. Vaccination strategy would be different for an orphan foal that didn’t receive colostrum or a foal from a mare that didn’t get vaccinated. This is something buyers might not think about when buying a weanling foal. They often ask about medical history
in terms of whether it has been ill or injured, but don’t always ask
if it has been vaccinated yet or if the mother was vaccinated or if it received good colostrum.
A well vaccinated mare will pass on protection to the foal via the colostrum.
VACCINATING FOALS
For optimum protection against foalhood diseases, it is very important that foals get adequate colostrum. “Ideally it should be from a mare that has been well vaccinated. This gives the foal protection for roughly 6 to
8 weeks or more, and then the foal needs to make his own antibodies,” says Wilson. A foal starts producing his own antibodies from birth, but the immature immune system doesn’t work very well at first, needing several weeks to get up to speed.
The antibodies from colostrum generally last longer—to keep the foal protected during that start-up time for his own immune sys- tem—but are not as effective past 4 to 6 weeks. “Since they are still present in his body, however, they can actually interfere with vac- cination if you vaccinate the foal too early. With a vaccine, we are giving an antigen, which is usu- ally an inactivated portion of the disease pathogen we are vaccinat- ing against,” says Wilson.
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EQUINE HEALTH