Influenza in Horses

Equine influenza

Equine influenza is caused by a highly contagious viral respiratory disease that causes flu-like symptoms. It is widespread and highly infectious, being prevalent throughout the year and affecting all types, ages and breeds of horses and ponies.

 

Equine influenza clinical signs

• Symptoms include:
• a high fever with temperature over 39.5oC
• reduced general condition
• cough
• runny nose
• lethargy
• swollen glands around the jaw

Flu can also cause your horse to become weak and vulnerable to other infections such as pneumonia. 

It is common for fevers to go up and down, so it is important to check fever charts. Take the temperature regularly and write down the degrees so that you don't have to worry about remembering the wrong ones.

 

How is it spread

Equine influenza is an airborne virus, so when an infected horse coughs or sneezes, the virus is released into the air where it can then be inhaled by other horses. It can also be spread directly through items such as water and feed buckets and even handlers which is what makes it so easy for other horses to become infected. For this reason, strict isolation measures should be put in place in the event of an outbreak to prevent other horses contracting the illness. 

 

Preventing the spread of equine influenza

The disease has an incubation of one to five days, meaning it can spready very quickly. For this reason, when bringing a new horse to your yard, it’s advisable to isolate them for a minimum of 21 days. 

• If your horse has equine influenza, or if there is an outbreak of equine influenza on your yard, you need to immediately put strict measures in place, which includes:
• Isolating infected horses until your vet confirms they are no longer infected, which could be up to 14 days.
• Horses who are infected should be kept away from other horses by at least 10 meters
• Keep a close eye on horses who may have been exposed to the disease by checking their temperature daily and looking for symptoms.
• Avoid travelling a sick horse
• Wear protective clothing and gloves when handling your horse
  Disinfect boots, equipment and your hands after handling a sick horse
• Avoid handling or touching other horses after dealing with a sick horse
• Don’t share tools, feed buckets or water troughs or other equipment

 

Treatment

There is no specific treatment for influenza in horses, but there are things you can do to help your horse feel better and recover quicker. Rest and supportive care from your vet are the key things, as well as making sure your horse’s stable is well ventilated and dust-free to prevent inflammation of the horse’s airways. 
The prognosis for horses with equine influenza is usually good, but it can take several weeks or longer before your horse fully recovers. It’s therefore important to introduce your horse back to work and competition slowly with advice from your vet. 

 

Equine influenza vaccine schedule 

It is recommended that owners vaccinate their horses routinely with a vaccine that covers the most common strains of equine influenza. Even horses who do not compete or leave the yard are at risk from infection from other horses. While the vaccine cannot promise full immunity, it will decrease the risk, and vaccinated horses are also likely to recover quicker if they contract the disease. 

Most horses require a booster either annually or six monthly. If a horse misses a booster, they will need to restart the programme. It is recommended that, after the first injection, the second one is given between 21 and 60 days, followed by a third injection between 150 and 215 days. 

For horses that compete, boosters will likely be required every six months, but check with your governing body or vet.