What is Strangles (Distemper)?
All horses are susceptible but young horses will generally develop more severe signs. If you suspect any horse of being affected with strangles, immediate isolate that horse and completely disinfect all surfaces that the affected horse came into contact with.
Strangles, also known as distemper in horses is considered to be one of the most common diseases in horses within the UK. It is an upper respiratory infection that is highly contagious and is caused by the Streptococcus equi bacteria. Characterized by severe inflammation of the mucosa of the head and throat, large amounts of thick pus and extensive swelling of the lymph nodes, strangles can occur through direct and indirect contact with a horse carrying the disease.
Book First Walk Free!
Symptoms of Strangles (Distemper) in Horses
Any horse suspected of having contracted strangles needs to be immediately quarantined. Contact your veterinarian without delay in order to have your horse tested if you notice any of these symptoms.
- Loss of appetite
- Difficulty eating or swallowing
- Elevated temperature, above 38.5 degrees C
- Nasal discharge that is thick and yellow in color
- Swollen glands in the throat
- Difficulty extending the neck
- Ruptured glands with the presence of pus or abscess material
Affected horses may only show some of these symptoms and the severity can be mild to extreme. Healthy adult horses may only show mild symptoms for a short period of time which is why you should do thorough assessments of your horses every few days.
Causes of Strangles (Distemper) in Horses
The Streptococcus equi bacteria cause strangles. Transfer of the bacteria can be completed by direct contact or through a shared environment. Shared water troughs, grain troughs, blankets, stalls, or any other surface that has come into contact with the discharge from any draining abscesses or nasal discharge can cause an unaffected horse to become infected.
Thankfully, the strangles virus is not airborne. The bacteria cannot be blown through the wind and travel long distances. It usually stays contained within a small area unless an infected horse is exposed to horses outside their herd.
Strangles has an incubation period of up to 14 days, although it usually only takes 3 to 10 days to appear. The appearance of abscesses can take up to a week to appear after the incubation period. If left untreated, a horse that survives will typically have the infection for about 3 weeks before signs of improvement. They will then be carriers of strangles as they will still carry the bacteria within them.
Diagnosis of Strangles (Distemper) in Horses
Your veterinarian will do a nasal swab and a cheek swab. Strangles will be confirmed by culturing the thick pus from the nose, the throat or any abscessed lymph nodes. Samples collected that have large amounts of mucus have come back as negative even if the horse is infected with strangles. If there are clinical symptoms that suggest your horse is infected with strangles, a repeat test should be conducted.
Treatment of Strangles (Distemper) in Horses
There is no set treatment plan for horses diagnosed with strangles. Each case is unique and requires different forms of treatment. Be sure to consult your veterinarian when deciding on the best treatment plan for your horse.
Once strangles has been confirmed, it is essential that the infected horse be quarantined away from all horses and other equine. Thoroughly disinfect any surface that the infected horse may have come into contact with. The best disinfectant to use is bleach or ammonia.
Your veterinarian will recommend supportive care that will include feeding a wet, sloppy food from the floor, not from their feed bucket. This allows for easier swallowing and also encourages drainage of pus from the throat.
Hot compresses will need to be applied to the abscesses on your horse’s throat area. This will help bring the infection to the surface and enables the abscess to rupture. Once the abscess ruptures it will have to be flushed and drained daily using an antiseptic solution. If the abscess does not rupture on its own, your veterinarian may need to lance it.
The use of antibiotics and anti-inflammatories have been used but with varying success. Consult your veterinarian about the use of antibiotics or anti-inflammatories and whether they would help your horse’s recovery from strangles.
The best way to fight strangles is to vaccinate your horse against it. If you have multiple horses, all horses should be vaccinated for strangles and be given regular boosters. Speak with your veterinarian regarding an immunization schedule to protect your horses.
Recovery of Strangles (Distemper) in Horses
Strangles is rarely fatal, but there can be complications that arise and can cause permanent damage to your horse. Follow all instructions given by your veterinarian and direct any questions regarding treatment to your veterinary clinic.
Preventing strangles from spreading is essential. Therefore, quarantine any horse that you suspect could have contracted strangles. Disinfect all surfaces that your infected horse may have come in contact with to ensure that strangles does not spread to other horses.