Equine Strangles

Last Updated on April 7, 2022 by Allison Price

Strangles is an upper-respiratory infection caused by Streptococcus, a strain of bacteria. Equi . Infections can cause fevers, nasal discharge, and swelling of the lymph nodes around your head and neck.


Nasal secretions and purulent drainage from abscesses can transmit the bacteria. It can happen directly (horse-to-horse) or indirectly (bacterial contamination of buckets and water sources, housing, and people). Between exposure and symptoms of infection, the incubation time is between 3 days to 2 weeks. Horses can be infected by other horses for weeks. Horses can be infected for up to 10 days. They may also become chronic carriers of the bacteria by shedding it in their nasal secretions and not showing any symptoms.


Penicillin is effective in treating Strangles bacteria. Banamine can be used to manage the fever. Due to the nature of Strangles, most horses will have to experience an abscess on their own. The infection can be prolonged and complications may occur if antibiotics are not administered before it ruptures. However, there are exceptions. An aggressive antibiotic treatment should be initiated if a horse develops Bastard Strangles (sometimes known as Bastard Strangles), purpura hemorhagica, or immune-mediated myositis.


Strangles can be highly contagious. Often, many horses will contract the disease within weeks. Farms with confirmed outbreaks are placed under quarantine. Animals are not allowed to leave the farm. Exposed or affected horses must be kept from other horses. Biosecurity includes:

Equine Strangles
  • After caring for sick animals, it is time to change your clothes and shoes.
  • Before visiting sick animals’ areas, it is important to take care of your health animals.
  • Only use approved equipment for sick animals
  • Thorough disinfection of all water sources, buckets, and stalls throughout the outbreak.

How can we tell if horses are healthy?

After the resolution of clinical signs, horses that have been infected with Strangles or were exposed to it are prohibited from leaving the premises for 30 consecutive days. It is common to recommend testing for carrier status, including serum protein M testing or nasopharyngeal washings.


  • Vaccination: A vaccine is available, but it is not always 100% effective. Your veterinarian will help you decide if vaccination is necessary.
  • Quarantines: Horses arriving at farms should be kept separate from other horses for 14-days and closely monitored for signs of infection.

Auctions should be avoided. Many auction houses regularly battle Strangles. These facilities are likely to have exposed horses.

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!