June 2009
Featured Articles

Foals Require Early Protection from Common Equine Diseases


We want our children to be healthy, so we provide them good nutrition, exercise and proper immunization against diseases. Much the same is true of foals. Foal owners need to immunize their foals against common diseases.

Foals are born without any natural immunity to diseases. But they quickly acquire passive immunity from their dams. Mares concentrate immunoglobulins in their colostrum (first milk) which contains antibodies against diseases. The newborn foal can absorb these rather large protein molecules for a short time after birth. So, it is critical they nurse soon and frequently after foaling. And, their dams have adequate, high­quality colostrum.

How can this be accomplished? First, immunize broodmares against common equine diseases 30 days before foaling. Also, for a month prior to foaling, house broodmares where they will foal. Both procedures allow the broodmare to produce antibodies for the diseases they are vaccinated for and those in the environment where they are housed. They will pass these antibodies to their foals through their colostrum. This process provides temporary immunity to the foal against these diseases.

In a few months, the foal’s immune system becomes functional. It will produce its own antibodies against diseases. For the body to know which antibodies to produce, it is necessary to immunize the foal against these diseases.

Most vaccinations require two initial injections. The second injection is given four weeks after the first dose. Normally, foals are not vaccinated until they are three months of age or older. Since most foals are born in late March to May, many are three months of age in early summer. Foals born earlier than this can be immunized whenever they are three months of age.

Foals are normally vaccinated for tetanus, and Eastern and Western Encephalomyelitis. In the past, they were also vaccinated for influenza. It is now recommended to not immunize foals for influenza if their dams were vaccinated 30 days prior to foaling. Wait until they are eight months old before vaccinating them the first time for influenza. They are given three injections with the first at eight months, the second at nine months and the third at ten months of age.

Some farms also immunize for rhinopneumonitis, a respiratory problem noted in foals in the fall. It requires two injections. The first can be given at three months of age with the second a month later.

Some owners also immunize foals for rabies and botulism.

You should discuss all vaccination programs with your veterinarian, to determine if it is advisable to vaccinate foals for rabies or botulism in your area.

It is recommended the second dose of any vaccine precede weaning by at least two weeks. Foals born early and weaned at four months of age should be vaccinated early enough to meet this criteria.