Everything You Need To Know About Horse Vaccines | Vaccination Guide

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Vaccines have become one of the most effective ways to prevent the number of harmful diseases for horses. For more than 75 years, your horses’ lives have been saved by this incredible ‘weapon’. It protects the body of horses by giving the ‘clue’ of bacteria, viruses, particular toxins, or other microorganisms to test the immune system in defending certain disease etiologies agents.

When the vaccine is delivered to the horse’s body, it will be recognized as foreign antigens. The body will respond by multiplying the white blood cells rapidly. The B cells introduce the antibodies into the blood stream and neutralize the antigens, then the T cells demolish the infected cells. Later when the actual disease-causing microorganism attacks the body, it can defend them by stronger and faster defense.

There two techniques of giving horse vaccine which are the intramuscular injection and intranasal vaccine. The most common way is intramuscular injection which distributes the vaccines into the muscle which then absorbed into the bloodstream. The intranasal vaccine is the technique of giving vaccines by a spray into the nostrils. It is so beneficial for defending the respiratory diseases like influenza and strangles.


Horse Vaccines

Horse Vaccines
Credit: Premier Equine Veterinary Service

Vaccination is such a complicated health care, so it is better to always have a talk to a veterinarian about the most proper vaccine that you need to give to your horses. You can also consider these four points of risks:

  1. Age

    Younger horses or under 5 years old are more at risk to have several diseases like West Nile virus or equine herpes virus.  The viruses easily attack their immune system. The older horses may have a stronger immune system to defend some diseases. However, older horses with a weak immune system also easily to be harmed by bacteria and viruses.

  1. Locations

    Some particular diseases can spread in specific locations, so the vaccination should also consider about the diseases that may spread in where the horse lives or shipped from.

  1. Career

    The horse’s occupation also influences his risk of certain diseases, whether you use the horse for competition or breeding. For instance, the horses that frequently travel from race to race or a broodmare have a high risk to have diseases from infected horses.

  1. Lifestyle

    Horses that mostly stay in a barn, and used occasionally for your own enjoyment have the lower risk to be affected by diseases.

Horse Vaccines Categories

horse vaccines
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Based on the recommendation from American Association of Equine Practitioners (AAEP), there are two categories of vaccination, the core and risk-based vaccines.


Core Vaccines

This vaccine is an ‘obligatory defense’ that should be given to your horses. It will protect your horses from some common equine diseases such as tetanus, rabies, Eastern Equine Encephalitis/Western Equine Encephalitis (EEE/WEE), and West Nile Virus.

  • Tetanus

    This paralytic illness is caused by Clostridium tetani which kinda lives everywhere in the backyard’s soil and horse’s feces, so it is hard to avoid. This anaerobic bacteria can fatally infect the wound. Vaccines with tetanus toxoid can safely protect the horse from the bacteria.

  • Rabies

    Though rabies in horses is less common than in another animal, but annual report always has this case, and it is such a fatal disease. It infects the central nervous system and spread through the infected animal. Moreover, rabies can easily spread to human through regular contact.

  • Eastern Equine Encephalitis/Western Equine Encephalitis (EEE/WEE)

    This is the brain and spinal cord inflammation that spread by mosquitoes. It is caused by viruses which are fatal and deadly. EEE mostly occurs in eastern and Midwestern states, and WEE happens mostly in the western states. Horses that live in the location where mosquitoes live massively need more frequent EEE or WEE vaccines.

  • West Nile Virus (WNV)

    The case was firstly reported in 1999 and killed about one-third of infected horses. Mosquitoes spread this virus which harms the equines’ nervous system. It will cause the behavioral change of the horse as it causes encephalitis.

Risk-based vaccines

This vaccine is given based on the horse’s circumstance and lifestyle. The diseases that can be handled by risk based vaccination include equine influenza, equine herpesvirus, strangles, and some less common diseases such as anthrax, rotavirus, Potomac horse fever, botulism, and equine viral arteritis.

  • Equine influenza

    The most common respiratory disease caused by the virus. AAEP recommends to give the vaccine to all horses, especially the ones that have contact with other horses.

  • Equine herpesvirus

    EHV or equine herpesvirus type1 and type 4 can cause rhino pneumonitis. The indications are fever, respiratory infection, abortion (in mares), and sometimes causes neurological complication.

  • Strangles

    This is a highly contagious disease that infects the lymph nodes. Streptococcus Equi bacteria is the cause of the disease with some indications like fever, cough, and depression. The disease spread from horse to horse.

  • Anthrax

    It spreads mainly in the Southwest which can be deadly to some horses.

  • Rotavirus

    The virus is a major cause of diarrhea in foal or under 3 months old. Giving the vaccine to a pregnant horse or newly born foal is the best way to prevent the disease.

  • Potomac horse fever

    Equine monocytic ehrlichiosis, which mostly occurs in warm weather. Horses that eat infected insects can be affected by this disease.

  • Botulism

    The disease mostly infects foals and caused shaker foal syndrome.

  • Equine viral arteritis.

    The virus can cause abortion in the broodmare and the stallion can carry the virus, and vaccination before breeding is a good prevention.


Horse Vaccines Side Effect

side effect vaccines horse
Credit: Winnipeg Free Press

In some cases, horse vaccines can cause a side effect like soreness and swell around the injected area. Some horse perhaps shows an allergic response to fever. It is important not to give unnecessary vaccines to lower the risk.

Horse vaccines are the effective tools to minimize the risk of your horses to be affected by certain diseases. Since it can’t be generalized to all horses, consulting to a veterinarian is the best way to give proper vaccination by determining some considerations.