Equine Influenza – what do you need to know?

It’s hot topic right now, social media is ablaze and vets phones are ringing off the hook.  Equine Influenza has been officially confirmed in a number of horses in the UK.  British horse racing suspended all race meets following this news and yards placed on lock down. Competitions have been cancelled over the weekend.  Competitors have withdrawn and refused to travel.

So with horse owners on red alert, Selwood Equine asks “What is equine influenza?” and “How much of a risk is there?”.

What is Equine Influenza?

It is the disease caused by strains of influenza A that are characteristic in the horse species. Equine influenza occurs globally, previously caused by two main strains of virus: equine-1 (H7N7) and equine-2 (H3N8).  The virus affects the upper and lower respiratory tract. (Wikipedia)

It is important to note that equine influenza is endemic in most of Europe all year round.  This is something the horse industry deals with 365 days a year.  There is always an outbreak somewhere. Horse owners in the UK are encouraged to vaccinate their horses at least annually with the recommended vaccines from their vets.  Vaccines are constantly changing as the virus changes and mutates.  Therefore the best protection is keeping up to date with regular vaccinations.

What are the symptoms to look out for?

Once the virus is inhaled by the horse it affects the lining of the horses airways.  A high temperature, followed by coughing, a snotty nose and enlarged glands under the lower jaw are all evident.  The damage caused by coughing creates ulcerations to the membranes of the airways. This can lead to infection.

With the membranes damaged, the drainage of mucus is not as efficient and detritus cannot be cleared. The horse will also exhibit sore or swollen eyes, depression and lethargy, lack of appetite and possible swelling in the lower legs.

How can it spread?

Equine influenza is highly contagious.  It is spread by the virus being coughed or sneezed out into the atmosphere by infected horses. Horses within the proximity inhale the virus in through their airways via air borne respiratory droplets . Direct contact with infected horses will also cause spread.  Contact from handlers and also via horse to horse – nose to nose for example. Contaminated surfaces and objects can also transfer the virus. Although the virus does not last long outside of the horses body.  The virus can spread over longer distances, up to 100m so in essence it can be ‘brought in with the wind’.

Shedding of the virus in nasal secretions will begin as soon as 24 hours after the animal is infected.  Shedding can continue for 7 to 10 days in some horses. Horses do not become carriers after this time.

How long is incubation?

Incubation is between one to five days, meaning that the virus can spread rapidly between horses.  For horses with confirmed cases isolated rest is vital.  One weeks rest is advised for every day that your horse has an elevated temperature. You cannot treat equine influenza with antibiotics, it is a virus.  Only secondary infections will require antibiotics.

How long can the virus live for?

The virus cannot live for long outside of the horses body, guidance is that it can live for up to 48 hours on hard surfaces.  Therefore correct isolation combined with the implementation of bio security measures will prevent further spread via objects or surfaces.  Disinfect to further protect.  The virus is also assailable to direct sunlight, heat and extreme cold.

Affected horses will be ill for anywhere between 2 to 10 days if no secondary infection presents.  Clinical signs usually resolve within 3 weeks.

Should you stop competing?

Even though racing has been abandoned temporarily, veterinary experts have advised the British Equestrian Federation that at this time it is not considered necessary to cancel other events.  For horse owners, this is an individual decision they will need to make.  Some centers may take the decision out of owners hands, cancelling their programme of events.

What action should you take now?

Be vigilant around your horses and monitor them for any changes.  As always good practice is essential.  Avoid direct contact with other horses and their belongings when out and about.  Make sure your vaccinations are up to date.  The BEF has suggested that if your horse had their annual vaccination over six months ago, that you may wish to discuss a booster with your vet.  This is not a rule or requirement, it is an advisory suggestion.


What if you think your horse has equine influenza?

If you see any of the signs listed above isolate the horse and contact your vet immediately. Apply bio security with regards to the affected horse, yard and handlers.  Any horse showing signs of possible equine influenza must not be transported off the yard.  This includes to competitions.  Notify anyone who has had contact with your horse over the previous week to two weeks.


In short, do not panic.  Be pragmatic and sensible. Maintain awareness of your horse(s), travel plans and what the updates are. Both locally and nationally.  This is a fluid situation – changes are constant.    Situations like this do not benefit from mass panic from the equine community to fuel them.  Always seek advice from a vet if you are unsure.

For further updates check the official BEF website.




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