Vaccination from Foal to Yearling

Immunization is a vital step in the protection of your horse from potentially debilitating or fatal infectious diseases. A good immunization program is essential to keeping your horses healthy. Vaccination provides a biological protective barrier between your horse and several infectious diseases. Vaccination dramatically reduces the risk of your horse getting infected, however it does not prevent disease in all circumstances. Vaccines are a preventative measure and should be administered before likely exposure rather than in the face of exposure. It should also be noted that not all horses in a herd will be protected to an equal degree or for an equal duration following vaccination.

Generally it takes 1-2 weeks after a full series of vaccinations are completed until your horse is fully protected. Following vaccination protective antibodies in the blood and other specialized immune system components guard against the invasion of specific diseases. These antibodies decline overtime. Therefore we use booster vaccines at regular intervals to maintain adequate protection. The booster interval varies depending on the disease, and exposure risk. Some diseases such as tetanus and rabies only require a once yearly booster to achieve protection. Other diseases such as Eastern and Western Equine Encephalitis (sleeping sickness) and West Nile Virus require more frequent booster intervals particularly for horses residing in endemic areas such as Florida.

Foals are generally not vaccinated before weaning as they derive their protection from maternal antibodies they receive via the colostrum. That is why it is critically important they receive adequate colostrum in the first hours after birth.

The specific immunizations required by a particular horse or horses depends upon several factors: age, use, breed, sex, general management, exposure risk and geographic location. Before implementing a vaccination policy you should consult with your veterinarian to design a protocol approriate to your horse’s individual needs.

In general we divide the various vaccines into two groups: Core vaccinations and non-core or risk-based vaccinations

Core Vaccinations

The American Veterinary Medicine Association defines core vaccinations as those “that protect from 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 the majority of patients.” The following vaccinations are recommended for every horse in Florida. These diseases are endemic to the state and pose a serious risk.

  • Tetanus
  • Eastern Equine Encephalitis (EEE) and Western Equine Encephalitis (WEE)
  • West Nile virus (WNV)
  • Rabies

Non-Core/Risk-Based Vaccinations

Non-core / Risk-based vaccinations are included in a vaccination program after the performance of a risk-benefit analysis. The use of risk-based vaccinations may vary regionally, from population to population within an area, or between individual horses within a given population. If unsure of the infectious diseases endemic to your area or if your horse is travelling to a new area, you should consult with your veterinarian to ensure your horses are adequately protected. The following equine vaccines are classified as risk- based:

  • Equine Influenza (Flu)
  • Equine Herpesvirus/Rhinopneumonitis
  • Strangles (Streptococcus equi)
  • Anthrax
  • Botulism
  • Equine Viral Arteritis
  • Potomac Horse Fever
  • Rotaviral Diarrhea

Our recommended vaccination protocol from foal to yearling

EEE, WEE, Tetanus, WNV

  • 3, 4, and 5 months old and then December
  • Booster every 6 months
  • EEE, WEE, WNV booster should take place in spring every year before peak mosquito season
  • Any horse that sustains a wound should receive a tetanus booster unless vaccinated for tetanus in the last 2 months


  • 6 and 7 months old and then January
  • Booster annually

Equine Influenza

  • Recommended for all horses on breeding farms, attending sales or shows, and in training barns
  • 6 months old, then booster every 6 months
  • Also recommended 30 days prior to sales/shows/shipping

Equine Herpesvirus / Rhinopneumonitis

  • Recommended for all horses on breeding farms, attending sales or shows, and in training barns
  • 5 and 6 months old, and December
  • Also recommended 30 days prior to sales/shows/shipping
  • Booster every 6 months Strangles
  • Only indicated for horses on farms where disease is endemic
  • Intranasal or intramuscular vaccination when over 6 months old, booster 1 month later, and again in December
  • Booster annually

Damian McEntee, DVM
Friday, February 3, 2012

EMC Icon

Get in touch

Contact us

O: (352) 873-7830
F: (352) 873-7700


Visit us

Equine Medical Center of Ocala
7107 West Hwy 326
Ocala, Florida 34482


Office hours

Mon - Fri (7:30am - 5:30pm)
Saturday (8:00am - 12:00pm) February to June
Closed on Sunday

200 OK


The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [no address given] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.