Knowing which horse vaccinations your horse actually needs, and getting the timing right, is one of the simplest things you can do to protect it from preventable, life-threatening disease. Equine influenza, tetanus, equine herpesvirus and strangles can all be controlled, or in tetanus’ case prevented outright, with a primary course and timely boosters. This guide explains the core and risk-based horse vaccines used in the UK, the FEI and BHA timing rules competition horses must follow, typical costs, and how to keep your horse’s passport in order so you never miss a dose.
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Why Horse Vaccinations Matter
Vaccination prepares the immune system to recognise specific pathogens before they cause disease. For horses kept in livery yards, taken to shows, or moved between premises, exposure is constant, so a properly maintained programme of horse vaccinations is the difference between a routine bug and a yard-wide outbreak.
The Royal Veterinary College, the British Horse Society and the FEI all align on the same principle: a primary course establishes immunity, and regular boosters keep it topped up. Miss a booster window and immunity drops; in many cases the primary course must be restarted from scratch.
- Tetanus is usually fatal once clinical signs appear, and it is entirely preventable.
- Equine influenza spreads on the wind for over a kilometre and shut down UK racing for six days during the 2019 outbreak.
- Equine herpesvirus (EHV-1) caused the 2021 Valencia outbreak that killed competition horses across Europe.
- Strangles is endemic in the UK horse population, according to the HBLB International Codes of Practice.
Vaccination does not replace good biosecurity. It works alongside isolation of new arrivals, routine temperature checks, and sensible horse care to stop disease before it reaches the rest of the yard. The National Office of Animal Health (NOAH) sets out the licensed equine vaccines available in the UK in its equine vaccination guidance.
Core Horse Vaccines Used in the UK
“Core” vaccines are those every horse should receive regardless of age, use or location. In the UK that means tetanus and equine influenza. Most yards combine the two as a single Flu/Tet booster, which is the backbone of nearly every horse’s vaccination record.
Tetanus
Tetanus is caused by the bacterium Clostridium tetani, which lives in soil and enters through wounds, including punctures, hoof injuries, and even tiny grazes a rider would never spot. Once clinical signs appear, namely stiff gait, locked jaw and raised tail, the prognosis is poor.
- Primary course: two injections, 4 to 6 weeks apart, from 5 months of age
- First booster: 12 months after the second primary injection
- Subsequent boosters: every 2 years for life
- After injury: what decides this is vaccination status, not months since the last dose. A horse that is up to date on its 2-yearly boosters does not need antitoxin; a horse that is unvaccinated or of doubtful status should be given tetanus antitoxin and started on a primary course if it has a wound or needs surgery
Equine Influenza
Equine flu is a respiratory virus that causes a high fever, harsh cough, and weeks of lost training. Vaccinated horses can still catch it but show milder signs and shed less virus, protecting the rest of the yard. For a fuller picture of the disease itself, see our guide to horse flu and how it spreads.
- V1: first injection from 6 months of age
- V2: 21 to 60 days after V1 (the BHA requires the same 21 to 60 day window)
- V3: 120 to 180 days after V2
- Annual booster: within 365 days of the previous dose; FEI requires within 6 months for horses competing
The interval rules have tightened in recent seasons to align UK practice with international standards, so always check current BHA and FEI calendars before a competition season, and see the RVC Equine Vaccination Service for the latest protocol.
Risk-Based Vaccines: Strangles, EHV, EVA and Rotavirus
Risk-based vaccines are recommended on top of the core schedule when the horse’s lifestyle warrants them. Discuss these with your vet at your annual booster visit, as your yard manager and discipline often dictate which apply.
Strangles
Strangles is a highly contagious bacterial infection caused by Streptococcus equi equi. It spreads via shared water troughs, tack, and human hands. The current UK vaccine (Strangvac) is given by intramuscular injection; the older product it replaced, Equilis StrepE, was injected into the submucosa of the upper lip and has been withdrawn.
- Two doses, 4 weeks apart, from 5 months of age
- Protection is short-lived: the datasheet gives a duration of immunity of 2 months after the second dose, and recommends repeating the two-dose course after 2 months in horses at high risk. This is not an annual vaccine — agree an interval with your vet based on the risk on your yard
- Particularly important for busy livery yards, riding schools and dealing yards
Equine Herpesvirus (EHV-1 and EHV-4)
EHV causes respiratory disease, abortion in pregnant mares, and, in its neurological form, paralysis. Vaccination reduces respiratory shedding and protects against abortion but does not fully prevent the neurological strain.
- Primary course: two doses, 4 to 6 weeks apart, from 5 months of age
- Boosters every 6 months for horses that travel or compete
- Pregnant mares: vaccinated at 5, 7 and 9 months of pregnancy with the inactivated vaccine
Equine Viral Arteritis (EVA)
EVA is largely a breeding-stock concern. Stallions can become persistent shedders. Pre-breeding blood testing to establish freedom from infection is set out in the HBLB International Codes of Practice, not by Defra. Routine vaccination is recommended for stallions and teasers, but UK supply of the EVA vaccine has been interrupted and the HBLB Codes currently advise enhanced serological testing of stallions in its place.
Rotavirus
Rotavirus causes diarrhoea in foals under 3 months. A pregnant broodmare can be vaccinated at 8, 9 and 10 months of pregnancy, with antibodies passing to the foal through colostrum. This is important on stud farms with a history of scours in foals.
Typical UK Horse Vaccine Schedule by Age and Use
The exact dates depend on what the horse does for a living. Below is a simplified UK horse vaccine schedule for the three most common scenarios.
Pleasure / Hacking Horse
- Annual Flu/Tet booster
- Tetanus alone every 2 years if separated from flu
- Strangles annually if at a busy livery yard
Competition Horse (BHA, BS, BD, BE)
- Equine influenza booster within 6 months and 21 days of last vaccination (FEI rule)
- BHA racing rule: V1, V2 (21 to 60 days), V3 (120 to 180 days after V2), then boosters not more than 6 months apart
- EHV-1/4 every 6 months strongly advised
- Tetanus on the standard 2-yearly cycle
Foal and Youngstock
- 5 to 6 months: first tetanus and influenza injections (or earlier if the mare was unvaccinated and colostrum quality is poor)
- 4 to 6 weeks later: second tetanus and influenza
- 4 to 6 months after V2: V3 influenza
- 12 months after V2: first tetanus booster
- Annual: influenza booster (or 6-monthly for competition)
If you are mapping out a programme for a foal, build it around the mare’s status. A well-vaccinated mare passes strong passive immunity through colostrum, which is why the first injections are timed for around 5 to 6 months once that maternal protection begins to wane.
Pregnant Mare
- EHV-1 inactivated vaccine at 5, 7 and 9 months of pregnancy
- Tetanus and influenza booster 4 to 6 weeks before foaling so antibodies pass through colostrum
- Rotavirus at 8, 9 and 10 months if stud history requires it
FEI, BHA and British Eventing Rules
The biggest reason a horse vaccine schedule fails is missing a competition deadline by a single day. Different governing bodies set different windows, and the rules have changed in recent seasons.
BHA (British Horseracing Authority)
- V1: from day 0
- V2: 21 to 60 days after V1
- V3: 120 to 180 days after V2
- Boosters: not more than 6 months apart
- The free BHA Vaccination Calculator works out exact valid dates.
The 21-to-92-day primary window and the once-a-year booster are the old racing rules and are still repeated all over the internet, including in earlier versions of this guide. The BHA’s current Vaccinations Code sets the primary course at 21 to 60 days, the first booster at 120 to 180 days after it, and every booster after that at no more than 6 months. A horse boosted only once a year is not correctly vaccinated for racing and cannot enter racecourse property.
FEI (International Disciplines)
- V1, V2 (21 to 60 days), V3 (within 6 months and 21 days)
- Boosters within 6 months and 21 days of the previous vaccine
- Last vaccination must be at least 7 days before the horse arrives at the venue
British Eventing, British Showjumping and British Dressage
BE, BS and BD all currently follow the 365-day annual booster rule for affiliated competition, with stricter intervals applying at championship level. Always cross-reference the rulebook for your specific class, and see the British Horse Society for grassroots guidance.
How Much Do Horse Vaccinations Cost?
Cost is one of the most common questions owners ask, and it varies by practice, region and which horse vaccines you choose. As a guide for the UK:
- Flu/Tet booster: typically £35 to £70 per dose, plus the vet’s visit or call-out fee
- Strangles (Strangvac): around £40 to £70 per dose
- EHV-1/4: around £40 to £70 per dose
- Primary courses cost more overall because they involve two or three injections in the first year
The cheapest route is a shared yard visit, where several horses split a single call-out fee. Many practices also offer annual healthcare plans that bundle the Flu/Tet booster with a dental check, which usually works out cheaper than paying piecemeal.
Supporting the Vaccine Response
A vaccine works only if the horse mounts an immune response to it. A few practical points keep that response strong:
- Don’t vaccinate a sick or stressed horse. Postpone if your horse has a temperature, is recovering from illness, or has just travelled a long distance.
- Time it around competition. Many horses feel slightly off for 24 to 48 hours after a flu vaccination, so don’t vaccinate the day before a major class.
- Maintain general health. Good feeding and nutrition, parasite control and dentistry all support immune function.
- Update the passport. The vet must record the batch number, date and signature in Section V of the equine passport for influenza, or Section VI for all other vaccinations, for the vaccination to be officially recognised. Section IX is the medicines and human-consumption declaration, not the vaccination record.
Stressful events, such as moving yards, weaning, transport over 12 hours, or intensive competition runs, all suppress immune function. Build a few rest days around major events to let immunity recover, particularly in older horses or those with conditions such as Cushing’s disease (PPID), where the vaccine response is reduced. Underlying illness such as equine asthma or a heavy worm burden can also blunt how well a horse responds, which is why routine health management and vaccination go hand in hand.
What to Do If a Booster Is Late
If a booster falls outside the valid window, the rules vary by vaccine and by governing body. The general principle:
- Tetanus over 2 years late: a single booster usually restores immunity, though some vets restart the primary course if the lapse is severe.
- Influenza booster over 365 days late: for racing and FEI competition, the primary course (V1, V2, V3) must be restarted in full. For pleasure horses, a single booster may be sufficient, but your vet decides.
- Strangles missed: the primary course must usually be restarted because protection is short-lived.
- EHV missed: restart the primary two-dose course.
Never let a horse compete on a lapsed certificate. Stewards check passports at affiliated events, and a single missed vaccination can disqualify the horse for an entire season.
Frequently Asked Questions
How often does a horse need vaccinating in the UK?
Most leisure horses receive one combined Flu/Tet booster per year. Tetanus alone is given every 2 years; equine influenza is annual, or every 6 months for FEI competition. Risk-based vaccines such as strangles or EHV are added on top depending on lifestyle.
Do horses really need vaccines every year?
Yes. Immunity from the flu vaccine fades within roughly 12 months, which is why an annual booster is the minimum for most horses and a requirement for affiliated competition. Tetanus immunity lasts longer, so that component is usually boosted only every 2 years, but skipping the annual flu top-up leaves the horse vulnerable and invalidates its competition record.
How long between a horse’s 1st and 2nd vaccinations?
For the equine influenza primary course, V2 is given 21 to 60 days after V1, and the BHA applies the same 21 to 60 day window for racing. The tetanus primary course is two injections 4 to 6 weeks apart. Your vet will usually align the two so the horse is covered with as few visits as possible.
Can I vaccinate my horse myself?
No. Equine vaccines are POM-V medicines in the UK, meaning they must be administered by a veterinary surgeon. Self-administered vaccinations are not recognised in the passport and invalidate competition eligibility.
Are there side effects to horse vaccinations?
Mild side effects are common: a small swelling at the injection site, slight stiffness in the neck, and a quiet day or two. Severe reactions (anaphylaxis, an abscess at the injection site) are rare but should be reported to your vet immediately. Avoid hard work for 24 to 48 hours after vaccination.
Do horses need a tetanus shot after every wound?
Not if the horse is up to date with its vaccinations — and up to date means within its normal 2-yearly booster cycle, not within the last six months. That six-month figure is a myth worth unlearning: the criterion vets actually use is vaccination status. A horse that is unvaccinated or of doubtful status is given tetanus antitoxin (immediate but short-acting protection) and started on a proper toxoid course (long-term protection). Always call the vet for puncture wounds, hoof injuries or anything contaminated with soil.
