What is strangles?
Strangles is a highly contagious and potentially serious respiratory disease that affects horses. It is caused by the bacteria Streptococcus Equi. The disease is characterised by the swelling and inflammation of the lymph nodes in the head and neck area, resulting in difficulty breathing and swallowing.
Strangles has an incubation period of 3-14 days. Infected horses can remain contagious for two to four weeks even if they are no longer displaying any symptoms. Horses should remain isolated until testing confirms that infection is no longer present.
Symptoms of strangles include:
- A temperature higher than 38.5 °C
- Swollen lymph nodes
- Pus filled abscesses appearing on lymph nodes
- Excess nasal discharge
- Breathing difficulties
- Coughing
- Difficulty swallowing
- Loss of appetite
- Lethargy
Whilst the majority of affected horses will make a full recovery, some cases of strangles can lead to secondary complications such as purpura hemorrhagica or bastard strangles which can be fatal.
Following infection, most horses will remain immune to strangles for at least one year however older horses and those with a compromised immune systems are more susceptible to reinfection.
What to do if you suspect your horse has strangles:
If you suspect your horse has strangles, they should be isolated from other horses until a diagnosis is either confirmed or ruled out. Once your horse is isolated, your vet should be contacted as soon as possible. A diagnosis of strangles is usually conducted based on clinical signs. Your vet is likely to carry out further tests such as swabs or blood samples to confirm a diagnosis.
It is also a good idea to alert anyone else who has recently been in contact with your horse that they have strangles i.e. farriers, physios, coaches, so that they can take measures to minimise the risk of spreading the disease on to other clients.
What to do if your horse has strangles:
If a case of strangles is confirmed, affected horses should remain in isolation until they are no longer contagious. The only way to ensure your horse is no longer infected with strangles is through use of further veterinary testing, once tests are clear then your horse can come out of isolation.
If one horse on a yard has strangles, the entire premises should be treated as high risk with no horses allowed to leave or outside horses permitted to enter until all those on site are no longer contagious.
Ideally anyone who handles a horse with strangles should not come into contact with any unaffected horses until the affected horse is no longer contagious. However, as this is not always possible, if you care for a horse with strangles and also need to tend to unaffected horses, it is important to wear appropriate PPE when handling the sick horse and follow strict biosecurity and disinfecting measures before coming into contact with an unaffected horse.
Preventing Strangles:
Whenever a new horse is introduced to a yard, it is important to quarantine them for at least two weeks. This helps prevent the spread of any infectious diseases, including strangles. When in isolation, horses should be monitored daily for any signs of potential infections. When staff work with a new horse it is important that they follow strict biosecurity measures before tending to other horses on the yard, including extensive hand washing and changing of clothes.
Ideally every horse should have their own grooming kit, feeding buckets, water buckets and tack. Sharing of equipment should be avoided where possible to minimise the risk of cross contamination. If you have to share equipment between multiple horses, it should always be disinfected between uses.
It is important that equine establishments hold accurate health records for every horse in their care. Health checks should be carried out on a regular basis and recorded. This can allow staff to notice any unusual patterns early so that they can take appropriate measures to reduce the risk of disease spreading.
Show grounds create the perfect environment for contagious diseases to spread with high volumes of horses arriving and departing on a regular basis. When travelling to a show it is a good idea to bring your own bedding, utensils, etc. Where possible direct contact between unfamiliar horses should be avoided.
In recent years, a vaccination for strangles has become available that provides short term immunity against the disease. Vets may not recommend this vaccine for every horse, therefore it is best to consult with your vet regarding what option is most beneficial to your own horse’s needs.
Carriers
A small number of horses who make a full recovery from strangles will retain the bacteria from the infection in their guttural pouches. Whilst these horses won’t display any clinical signs of the condition, they can still infect other horses. It is difficult determine whether a horse is a carrier of strangles or not and this has to be diagnosed through veterinary testing.
Carriers are usually treated through a more invasive procedure known as a guttural pouch endoscopy. If you suspect your horse is a carrier of strangles, it is important to contact your vet in order to confirm or rule this out, all suspected carriers should be isolated as if they were displaying symptoms.
Awareness of strangles
Whilst Strangles can be a worrisome and challenging illness to manage, with greater awareness and education, owners are better equipped to minimise their horse’s risk of exposure to the disease and can be prepared to implement correct isolation and treatment procedures should a case develop. Isolation facilities and procedures are now standard at many yards, this allows for much better containment of infectious diseases such as strangles.