What is strangles?
Strangles in horses is a respiratory bacterial infection caused by Streptococcus equi. Strangles gets its name from its characteristic symptom of enlarged lymph nodes surrounding the upper airways, which can cause horses to suffocate.
Strangles remains widespread today. It is one of the most commonly diagnosed equine infectious diseases worldwide.
How is strangles in horses contracted?
Strangles is highly contagious and is transmitted directly between horses via the nasal discharge of an infected horse. Horses can shed the bacterium for months or even years without showing signs or symptoms, while still transmitting it to other horses.
Indirect transmission is also possible if equipment or objects become contaminated and are shared between horses, or by a handler who has hands or clothing contaminated by an infected horse.
Clinical signs and symptoms of strangles in horses
Clinical signs and symptoms of strangles include:
Swollen lymph nodes
(typically submandibular and retropharyngeal) that can develop abscesses
Loss of appetite
Occasionally the infection spreads to lymph nodes in the thorax or abdomen, resulting in a complication known as "bastard strangles."
Prevention and treatment of strangles in horses
The traditional treatment for strangles in horses is a course of antibiotics, such as penicillin, although the efficacy of this treatment remains controversial. Antibiotics are ineffective at eliminating the microbe completely and may result in a reduced immune response, potentially making horses treated with antibiotics more susceptible to relapse.
Vaccination helps to reduce the risk of strangles. Strangles is highly contagious and will inevitably infect all exposed horses. In addition to vaccination, following a strict biosecurity protocol can help reduce the risk of a strangles outbreak or minimize the impact of an emerging outbreak.
A strangles control protocol may include:
about whether a vaccination plan to help protect your horse against strangles is needed.