Horse Strangles: Managing a Highly Contagious Disease

Strangles is one of the most contagious equine diseases, causing significant welfare harm and requiring strict biosecurity to control spread.

Key Facts

Strangles is caused by Streptococcus equi subspecies equi - one of the most contagious equine diseases
It causes fever, nasal discharge, and painful submandibular lymph node abscesses that may rupture
Bastard strangles involves abscess formation in internal organs and carries a poor welfare prognosis
Horses typically recover but may carry S. equi in the guttural pouches for months to years, shedding intermittently
Vaccination reduces disease severity but does not fully prevent infection in exposed horses
Strict isolation of affected horses and biosecurity protocols prevent spread within premises

Welfare Considerations

Strangles causes significant acute welfare harm through fever, loss of appetite from throat pain and lymph node pressure on swallowing, painful abscess formation and rupture, and the distress of respiratory compromise from enlarged lymph nodes. Bastard strangles - where abscesses form in the chest or abdomen rather than around the head - causes serious systemic illness with high mortality. The highly contagious nature of strangles means that a single case on a premises with inadequate biosecurity can affect an entire yard in weeks, multiplying the welfare harm many times over. Strict isolation, guttural pouch endoscopy to identify carriers, and depopulation protocols prevent reintroduction to a clear premises.

What You Can Do

Isolate any horse with fever, nasal discharge, or swollen lymph nodes immediately
Notify your veterinarian and other yards where the horse has recently visited
Implement strict biosecurity including dedicated equipment, hand washing, and restricted yard access
Have carrier horses tested by guttural pouch endoscopy and lavage before returning to a yard
Discuss vaccination with your veterinarian for horses at high strangles risk
Provide pain relief for horses with painful abscesses under veterinary guidance