Vaccination is essential in preventing some important disease such as influenza and tetanus. Many horses must have a current vaccination against influenza in-order to compete. Vaccinations can also be given to help prevent herpes virus and rotavirus.
There is an old saying that prevention is better than cure and one of the main weapons in our arsenal for preventing disease is vaccination.
Vaccinating against disease was discovered in 1796 by the medical pioneer Edward Jenner who acted upon the observation that milkmaids who caught the cowpox virus did not catch smallpox. All modern vaccines are based on this principle.
The most common diseases for which there are vaccines available to horses are listed below.
Influenza is a viral infection affecting young horses (most commonly 2 to 3 years-old). The virus attacks the respiratory system producing a high fever, runny nose and a cough. Though rarely fatal this can be a very debilitating disease.
For your horse to produce an effective immunity against influenza it must have an initial primary course of three vaccinations and to provide an ongoing immunity a booster vaccination must be given annually. You can start vaccinating a horse at any time once it is over the age 5-months-old. The timings for the booster vaccinations must be adhered to exactly and are listed below:
- 1st vaccination: This vaccination can be given to any horse over the age of 5 months.
- 2nd vaccination: To be given between 21 and 92 days after the 1st vaccination. A rule-of-thumb is to time the second vaccine between 4-6 weeks after the first vaccine. Please note if you are vaccinating against tetanus in combination with flu (and this is the most common type of vaccine given to horses) the minimum period between the first and second vaccines is extended to 28 days.
- 3rd vaccination: To be given between 150 and 215 days after the second vaccination. A rule-of-thumb is to time the third vaccination 6 months after the second vaccination.
- Annual booster: To be given within 1 calendar year following the third vaccination.
It is your responsibility to have the vaccinations at the correct time. We will try our absolute best to remind you when your horse requires its vaccinations. We provide the dates that the vaccinations are due on the invoice for each vaccination. We also send out vaccination reminders. Despite our best efforts these systems are not infallible and it remains your responsibility.
The Jockey Club and FEI organisations dictate that a horse must be vaccinated against influenza in order to compete in competitions held under their rules.
Under Jockey Club rules a horse may compete 7 days following the second booster vaccination of the primary course. Additionally the horse must have a third booster vaccination and have its annual booster vaccination within a calender year.
Under FEI rules a horse may compete 7 days following the second booster vaccination of the primary course. Additionally the horse must have a third booster vaccination and have a booster vaccination every 6 months.
The 6 monthly booster must be given within 6 months and 21 days. The FEI will impose fines for those horses competing that have had the booster injection outside this window.
All horses should be vaccinated against tetanus. This is a fatal disease of horses which is now rarely seen due to most of the horse population being vaccinated against this disease.
Tetanus is a bacterial infection that can infect any wound. The disease is rapidly fatal causing the muscles of the horse to stop working by going in to spasm. It is very difficult (and very expensive) to treat.
Effective immunity against tetanus requires a primary course of two vaccinations. Following this primary course a booster vaccination is given every two years:
- 1st vaccination: Can be given to any horse over the age of 5 months. In certain situations it may be appropriate to start vaccinating earlier than 5 months. Please see the mare and foal section or call the office to discuss your individual situation when you have a foal.
- 2nd vaccination: To be given between 28 and 90 days after the 1st vaccination.
- Every other year booster: To be given within 2 calendar years of the second vaccination.
If your horse has not been vaccinated and sustains a wound tetanus can be prevented by giving tetanus anti-toxin. This is not the same as a vaccination but will protect your horse against tetanus for approximately 3 weeks.
EQUINE HERPES VIRUS (EHV)
Equine Herpes Virus has 5 types labelled EHV 1-5. EHV 1 and EHV 4 are of most importance and they are the only types which can be vaccinated against.
EHV 1 and 4 can cause a respiratory infection much like Flu. However of much more significance these viruses can cause abortion in pregnant mares and a neurological disease.
Before a vaccination against EHV 1 and 4 became available each year outbreaks of abortions would occur in the major stud areas of the world (for example Newmarket in the U.K. and Kentucky in the U.S.A.). Effective vaccination has prevented these outbreaks. Individual horses are at a much reduced risk of infection but there still remains a small risk.
To provide effective immunity against abortion caused by EHV 1 and 4 a course of three vaccinations must be given during the 5th, 7th, and 9th months of pregnancy.
To provide effective immunity against respiratory disease caused by EHV 1 and 4 a primary course of 2 vaccinations must be given. Following this primary course a booster vaccination must be given every 6 months.
- 1st vaccination: Can be given to any horse over the age of 5 months.
- 2nd vaccination: To be given 4-6 weeks after the 1st vaccination.
- 6 month booster: To be given within 6 calendar months of the 2nd vaccination.