Strangles in horses

Craig Wood, University of Kentucky

Strangles is a highly contagious upper respiratory infection in horses. The cause has been identified as a bacteria. The disease has a low mortality rate, yet the economic ramifications due to long recovery periods can be great. The disease is contracted through environmental contamination, nasal discharge, or direct contact with infected animals.

Clinical Signs


1. high fever of 103 to 106 F
2. loss of appetite
3. a moist cough
4. clear nasal discharge that becomes yellow
5. difficulty in breathing and swallowing (as if strangling, hence the name)
6. swelling of submandibular lymph nodes that rupture.


This upper respiratory inflammation then spreads to the submandibular lymph nodes (below the jaw), which eventually abscess. Symptoms can range from minor to major. The most severe form of strangles involves inflammation of all lymph nodes



Treatment consists of supportive care, which involves keeping the animal warm and dry, isolating it from other animals, and offering it soft foods. Hot packing of the abscesses speeds up formation of pus. The antibiotic of choice is penicillin if used before abscess development. Penicillin used after abscess formation slows recovery. Strangles is usually not fatal.




There is a vaccination available for strangles, yet efficacy is low and the duration is short. The best prevention is to isolate new animals, optimally for a month. Any horses with upper respiratory signs should be avoided and/or watched closely for further problems.