What Is Strangles?

Strangles is caused by the bacterium Streptococcus equi.

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It mostly commonly occurs in younger horses, but cases do occur in older horses as well. Transmission is by contact with infected animals, so isolation of affected horses is vital in preventing the spread of the illness.

The incubation period of the infection is three to six days, after which the animal will start to show a loss of appetite and a high temperature. A watery or purulent nasal discharge may also be seen at this stage. From here, infection spreads to the lymph nodes of the head and neck, causing swelling and sometimes the formation of abscesses. The horse may develop difficulty swallowing. Horses are normally uncomfortable with strangles and likely hold their head low, with their nose stretched forwards.