Why do we vaccinate our horses?

Equine Influenza is a very commonly occurring virus. It is highly contagious and can be life threatening if contracted by very young or elderly horses or horses that have not been vaccinated.

Vaccinating your horse does not stop your horse from contracting the virus but it can reduce the clinical signs of the disease.   

Clinical signs of Equine Influenza can include:

• Fever
• Off colour, not eating or drinking
• Sweating or shivering
• Coughing or discharge from the nostrils
• Secondary bacterial lung infections and even death.

What to do if your horse is showing signs of equine flu…

If your horse is showing signs of flu then the best thing to do is call your vet as soon as possible. If they also suspect flu, they will then be able to take a swab from inside your horse’s nose and send it to the AHT where we will test it for flu free of charge.
Horses shed the most virus in the first few days of infection, so the sooner your vet takes a sample, the more likely they are to get a positive test result. Paired blood samples are also useful for making a diagnosis, especially if your horse is not sampled for several days after it first shows signs of infection.

Diagnosis and treatment

Once your vet has received the result, they will be in a better position to advise you on the most appropriate treatment and on the long term recovery for your horse. They will also help you identify other susceptible animals and suggest isolation strategies to limit the spread of the disease.


It takes between 50-100 days for the lining of the respiratory tract to fully recover after a horse has been infected with flu. During this period they should not undergo any stress or strenuous exercise as they will be predisposed to developing other respiratory infections.
A good rule of thumb is for every day that they had a temperature they will need at least a week off from exercise.

Similar to human influenza viruses, the virus can mutate producing different “strains” and it is very important that your horse is vaccinated with the most up to date vaccination available.

If you have concerns about Equine Influenza then contact your vet for further advice.  

Further advice can also be found here.

Clostridium Tetani (Tetanus)

Tetanus is caused by the bacteria, Clostridium tetani which is found in the soil. The bacteria can enter the horse’s bloodstream via small, infected wounds.

Clinical signs of Tetanus:

• vague stiffness and unwilling to move.
• This can then progress to muscle spasms of the head and neck resulting in difficulty eating and drinking, nostril flaring and a wide-eyed expression.
• Finally, it can progress to generalised trembling, violent, whole body spasms in response to sudden movements or noise and death.

Approximately 90% of unvaccinated horses that develop tetanus die.

Vaccination protocols:

There is a recognised vaccination protocol as set out by the regulatory authorities n the UK.
1. First vaccination at around 6 months of age
2. Second vaccination 21 to 92 days after the first vaccination
3. Third vaccination 150 to 215 days after the second vaccination
Following on from this initial protocol horses must be vaccinated within one year of the third vaccination and every year after that.

In light of the current outbreak experts are advising that horses be vaccinated within the last six months so please check your horses passport vaccination pages.

If you have concerns about Influenza or Tetanus then contact your veterinary surgeon or contact us here at Equine Health Direct for further advice.

Further information on Equine Influenza can be found here. The Animal Health Trust are currently offering free laboratory testing for Equine Influenza.  Further information can be found here.