Strangles (Streptococcus equi subspecies equi) Disease Guidelines

Strangles is a highly contagious bacterial disease of horses caused by Streptococcus equi, commonly producing fever, swollen lymph nodes, and purulent nasal discharge. It spreads easily through direct contact or contaminated equipment, and nearly all susceptible horses exposed will become infected. Most horses recover within a few weeks with supportive care, but about 10% become long-term carriers that can continue to spread the disease.

Diagnosis relies on PCR testing and/or bacterial culture of upper respiratory and abscess samples, whereas guttural pouch samples are key for identifying carriers. Effective control depends on strict biosecurity practices, isolation of affected horses, and careful management of new arrivals, while vaccination may help prevent disease but is not recommended during outbreaks.