Strangles is one of the most common equine diseases globally, and it is extremely contagious.

Strangles affects the horse’s upper respiratory tract and it strikes indiscriminately, regardless of age, sex or breed. It is also extremely difficult to contain once an outbreak starts.

Signs to Look Out For

The main clinical signs are as follows:

• High temperature (over 38.5c);

• Lethargy;

• Dull and depressed;

• Lowered head and neck;

• Coughing;

• Thick and discoloured discharge from the nose;

• Swelling of the lymph nodes which are found in the space between the head and neck;

• Abscesses in the lymph nodes which can burst into the horse’s guttural pouch (the air pockets at the back of the horse’s throat) and then drain out through the nostrils.

Causes

Strangles is caused by a bacteria called Streptoccus equi. It is not a virus.

Strangles is highly contagious so it can easily spread from horse to horse. As it is not airborne, it is usually transmitted through a cough or snort or infected material.  It can also be passed on indirectly via surfaces, equipment, water, and humans.

Strangles gets further complicated due to the fact that some horses become ‘strangles carriers’ after having the illness. This means that they still have the bacteria in their respiratory system, but seem healthy and well. These carriers can then shed the bacteria intermittently. This is why it is essential that all horses are checked once they recover from strangles to prevent infection and reinfection.

Treatment

If you suspect your horse may have strangles, isolate them immediately and contact your vet, who will most likely carry out one or more of the following diagnostic tests to determine whether strangles is present:

• Swabs of nasal or abscess discharge;

• Guttural pouch endoscopy;

• Blood samples.

If strangles is diagnosed, it is vital that veterinary treatment is administered as soon as possible. Medication will be needed to help relieve the severity of symptoms and there may be other issues that will also need specific treatment.

Many horses will be very ill while they are infected, but will usually start to improve after two or three weeks.  Unfortunately, strangles can be fatal.

Repercussions from strangles cases can be far reaching, which is why strict quarantine measures need to be put in place immediately. Yards can be seriously impacted if an outbreak takes place.

Prevention

The best way to prevent strangles is through good and robust bio-security measures. Horse owners and yard managers should take steps to reduce their strangles risk, and the following measures should help:

• Screening new horses on a yard by keeping them in quarantine for two to three weeks and/or screening blood tests;

• Travelling safely by cleaning and disinfecting shared vehicles between trips and by being careful about travelling with horses from other yards;

• Being infection aware at events;

• Avoiding sharing facilities and equipment with other owners;

• Making yourself aware of strangles and the clinical signs.

There is a strangles vaccination available. The most recent vaccine, Strangvac, was launched in 2022 and is up to 94% effective at preventing or reducing infection in vaccinated horses. It consists of two vaccines given four weeks apart.  Speak to your vet for more information.

Lastly, we need to mention Strangles Awareness Week, which is a global collaborative effort to prevent and manage strangles. It is a great place to get involved and learn more.

www.redwings.org.uk/strangles/strangles-awareness-week