Vaccinations: flu, tetanus and more

Which vaccines?

Vaccines work by showing the horse's immune system a harmless part of a disease-causing organism, so it makes antibodies ready for the real thing, World Horse Welfare explains. Your vet will advise on your horse's needs. The British Horse Society's recommendations:

World Horse Welfare says flu and tetanus vaccinations should be part of every horse's annual health plan.

Equine influenza

Flu is a highly contagious respiratory virus, spread in droplets when infected horses cough. The BHS says it can be carried on the wind for several kilometres, as well as on people, equipment and vehicles. Signs appear within one to five days, so it can spread through a yard very quickly, particularly among unvaccinated horses. See Common illnesses.

Vaccination reduces how ill a vaccinated horse gets if infected, and how much virus it spreads to others. British Equestrian notes that flu is often brought onto a yard by an unvaccinated horse.

The first course

Flu protection starts with a primary course of three injections over the first year, followed by boosters. From 1 January 2024, on British Equestrian's advice, many equestrian organisations shortened the gaps allowed between the first three injections. As an example, these are the intervals in British Riding Clubs' 2026 rules:

Courses started before 1 January 2024 may follow the older intervals instead (21–92 days, then 150–215 days). If your horse's vaccinations are already current and correct, the change doesn't affect it.

Boosters

Protection from a flu vaccine is strong but short-lived, so horses need regular boosters. The BHS's advice:

• As a minimum, vaccinate every horse annually, no more than a year apart. British Equestrian says the same, even for horses that never leave the yard.
• Six-monthly boosters are an option, and keep antibody levels higher for better protection.
• Don't let a booster lapse. Even one day late can mean restarting the primary course, which is costly.

Before your vet vaccinates

• Have the passport ready, so the vaccination can be recorded in it.
• Tell your vet if your horse seems off colour, for example lethargic or not eating as usual. It may be incubating a disease, and vaccinating then could cause a reaction.

Competing and shows

Vaccination rules differ between organisations, and it is the owner's responsibility to check them. World Horse Welfare notes that competing horses may need flu vaccines every six months. Some rules also bar horses from competing for a few days after a vaccination: British Riding Clubs, for example, doesn't allow a horse at its qualifiers or championships if it was vaccinated in the six days before.

You must carry your horse's passport when you transport it, and shows may check vaccinations. If your horse doesn't meet the rules, you're unlikely to be allowed to compete. Check the vaccination rules of any venue you hire, too. See Travel rules and paperwork.

Herd immunity

The more horses are vaccinated, the less flu can spread. British Equestrian says that if more than 70% of the country's horses were vaccinated, flu couldn't get a foothold. Both British Equestrian and the BHS estimate that only around 40% of UK horses are vaccinated against flu. Vaccinating your horse protects it, and every other horse it meets.

EHV and strangles

EHV. Vaccination can help prevent both the respiratory disease and the abortions caused by EHV-1 and EHV-4, and reduces the amount of virus an infected horse sheds. There is no vaccine registered to prevent the neurological form of EHV-1. Pregnant mares are a particular concern: speak to your vet.

Strangles. The BHS describes the UK vaccine as safe and effective: it reduces the risk of infection and limits how ill a horse gets, and it won't cause a false positive if your horse is later tested for strangles. British Equestrian advises asking your vet whether the vaccine is available and appropriate, based on a risk assessment.

Neither replaces good hygiene. Keep up the biosecurity habits in Preventative care.