VACCINATIONS FOR FOALS
**ALL VACCINATION PROGRAMS SHOULD BE DEVELOPED IN CONSULTATION WITH A LICENSED VETERINARIAN**
The two categories below reflect differences in the foal’s susceptibility to disease and ability to mount an appropriate immune response to vaccination based on the presence (or absence) of maternal antibodies derived from colostrum. The phenomenon of maternal antibody interference is discussed in the text portion of these guidelines.
CORE VACCINATIONS protect against diseases that are endemic to a region, those with potential public health significance, required by law, virulent/highly infectious, and/or those posing a risk of severe disease. Core vaccines have clearly demonstrated efficacy and safety, and thus exhibit a high enough level of patient benefit and low enough level of risk to justify their use in all equids.
| Disease | Foals and Weanlings (<12 months of age) of mares vaccinated in the prepartum period against the disease indicated | Foals and Weanlings (<12 months of age) of unvaccinated mare or lacking vaccination history | Comments |
|---|---|---|---|
| Tetanus | 3-dose series:
1st dose at 4 – 6 months of age Annual Revaccination | 3-dose series:
1st dose at 3 – 4 months of age Annual Revaccination | |
| Eastern / Western Equine Encephalo- myelitis (EEE/WEE) | 3-dose series:
1st dose at 4 – 6 months of age | 3-dose series:
1st dose at 4 – 6 months of age | Note: Primary vaccination series scheduling may be amended with vaccinations administered earlier to younger foals that are at increased disease risk due to the presence of vectors.
* Foals in the Southeastern USA: The primary vaccination series can be initiated with an additional dose at 2-3 months of age due to early seasonal vector presence. |
| West Nile Virus (WNV) | 3-dose series:
1st dose at 4 – 6 months of age Annual Revaccination | 3-dose series:
1st dose at 4 – 6 months of age Annual Revaccination | Note: Primary vaccination series scheduling may be amended with vaccinations administered earlier to younger foals that are at increased disease risk due to the presence of vectors.
* Foals in the Southeastern USA: The primary vaccination series can be initiated with an additional dose at 2-3 months of age due to early seasonal vector presence. |
| Rabies | 2-dose series:
1st dose at 6 months of age Annual Revaccination | 1 dose
Annual revaccination | The recommendation for a 2-dose initial series in foals from mares vaccinated with rabies within the year prior to foaling is to address the potential for maternal antibody interference. Rabies products are efficacious for at least 12 months (depending on manufacturer) based on efficacy studies with naive foals (no maternal antibodies). |
RISK-BASED VACCINATIONS can be found on the following pages
RISK-BASED VACCINATIONS are those having applications which may vary between individuals, populations, and geographic regions. Risk assessment should be performed by, or in consultation with, a licensed veterinarian to identify which vaccines are appropriate for a given horse or population of horses. The listing of a vaccine here is not a recommendation for its inclusion into a vaccination program. Vaccine scheduling is provided for use after it has been determined which, if any, risk-based vaccines are indicated. Note: vaccines are listed in this table in alphabetical order not in order of priority for use.
| Disease | Foals and Weanlings (<12 months of age) of mares vaccinated in the prepartum period against the disease indicated | Foals and Weanlings (<12 months of age) of unvaccinated mare or lacking vaccination history | Comments |
|---|---|---|---|
| Anthrax | Not applicable. As it is not recommended to vaccinate mares during pregnancy there will be no foals of mares vaccinated prepartum | No age specific guidelines are available for this vaccine.
Manufacturer’s recommendation is for primary series of 2 doses administered subcutaneously at a 2 to 3-week interval. | Antimicrobial drugs must not be given concurrently with this vaccine.
Caution should be used during storage, handling and administration of this live bacterial product. Consult a physician immediately should accidental human exposure (via mucus membranes, conjunctiva or broken skin) occur. |
| Botulism | 3-dose series:
1st dose at 2 – 3 months of age | 3-dose series:
1st dose at 1 – 3 months of age | Maternal antibody does not interfere with vaccination; foals at high risk may be vaccinated as early as 2 weeks of age. |
| Equine Herpesvirus (EHV) | Inactivated or modified live vaccine
3-dose series: 1st dose at 4 – 6 months of age Revaccinate at 6-month intervals | Inactivated or modified live vaccine
3-dose series: 1st dose at 4 – 6 months of age Revaccinate at 6-month intervals | |
| Equine Viral Arteritis (EVA) | Colt (male) foals: Single dose at 6-12 months of age (see comments) | Colt (male) foals: Single dose at 6-12 months of age (see comments) | Prior to initial vaccination, colt (male) foals should undergo serologic testing and be confirmed negative for antibodies to EAV. Testing should be performed shortly prior to, or preferably at, the time of vaccination.
As foals can carry colostral derived antibodies to EAV for up to 6 months, testing and vaccination should not be performed prior to 6 months of age. |
| Equine Influenza | Inactivated vaccine
2 or 3-dose series: Dependent upon the manufacturer’s product recommendation, the vaccine is an initial two or three dose series with a 3 to 4-week interval between doses (IM) starting at 4-6 months of age. Modified live vaccine Administer a single dose (IN) in foals 11 months of age or older Revaccinate at 6-12month intervals based on risk | Inactivated vaccine
2 or 3-dose series: Dependent upon the manufacturer’s product recommendation, the vaccine is an initial two or three dose series with a 3 to 4-week interval between doses (IM) starting at 4-6 months of age. Modified live vaccine Administer a single dose (IN) in foals 11 months of age or older Revaccinate at 6-12month intervals based on risk | An increased risk of disease may warrant vaccination of younger foals. Because some maternal anti-influenza antibody is likely to be present, a complete series of primary vaccinations should still be given after 6 months of age. |
| Leptospirosis | 2 dose series:
1st dose at 6 months of age Annual revaccination | 2 dose series:
1st dose at 6 months of age Annual revaccination | Safety has been demonstrated in foals 3 months of age. The effects of circulating maternal antibody and vaccination have not been determined. |
| Potomac Horse Fever (PHF) | 2 dose series:
1st dose at 5 months of age | 2 dose series:
1st dose at 5 months of age | If risk warrants, vaccine may be administered to younger foals. Subsequent doses are to be administered at 4-week intervals until 6 months of age. |
| Snake Bite | Please see guidelines for additional information | Please see guidelines for additional information | |
| Strangles
Streptococcus equi | Killed vaccine
3 dose series: 1st dose at 4-6 months of age Modified live vaccine 3 dose series administered intranasally: 1st dose at 6-9 months of age | Killed vaccine
3 dose series: 1st dose at 4-6 months of age Modified live vaccine 3 dose series administered intranasally: 1st dose at 6-9 months of age | Vaccination is not recommended as a strategy in outbreak mitigation.
If risk warrants, the modified live vaccine (MLV) may be safely administered to foals as young as 6 weeks of age. However, vaccine efficacy in this age group has not been adequately studied. If MLV is administered to younger foals, a 3rd dose of vaccine should then be administered 2 – 4 weeks prior to weaning. The risk of vaccine-associated adverse events is increased when the MLV product is administered to young foals. |
Vaccinations for Foals were developed by the American Association of Equine Practitioners (AAEP) Infectious Disease Committee. These guidelines and charts were reviewed and updated by the committee & Vaccination Guidelines Subcommittee and approved by the Board of Directors in 2020.
Please note that updates to these guidelines and charts may occur online at anytime and should always be referenced there for the most current version at www.aaep.org.
