A vaccine protocol should be established before preparing a mare for breeding. Many variables may effect the selection of vaccines used and when they are given, before, during and after gestation. Mares should be included in a general vaccination program, similar to all horses at your site. All horses should be vaccinated annually for Tetanus, the encephalidities (EEE and WEE) and West Nile Virus. In Southern Oregon, horses should also be vaccinated annually for Rabies. If your horses are exposed to other horses, such as at horse shows, trail rides or going to other breeding farms, they should receive vaccines for influenza and rhinopneumonitis every six months. Other vaccines, such as Lyme Disease, Strangles or Potomac Horse Fever, may be used if indicated in your specific farm or region.
In addition to the standard healthy horse vaccination program, pregnant mares should receive additional vaccinations to prepare their immune system to provide optimal protection to their foal. If influenza and rhinopneumonitis vaccines are indicated, these vaccines should be provided to the mare at the 5th, 7th and 9th months of gestation. At 4 – 6 weeks prior to foaling date, the mare should receive a full slate of vaccines – tetanus, EEE, WEE, WNV, rabies, influenza and rhinopneumonitis (if indicated) – to stimulate optimal antibody production for the colostrum.
If the mare has been appropriately vaccinated as above, the foals are generally protected for the vaccinated diseases for up to six months. Thus, the foal vaccination program should begin at 4 – 6 months of age so they will develop their own protection moving forward. If your mare has not been vaccinated as above, your foal’s vaccinations should begin earlier at 2 months of age.