Horse Strangles: Welfare Impact and Prevention

Strangles is a highly contagious bacterial infection causing painful abscesses in horses that is largely preventable with vaccination.

Key Facts

Strangles is caused by Streptococcus equi equi and spreads rapidly through direct and indirect contact
Affected horses develop painful lymph node abscesses that can compress the airways in severe cases
Recovery typically takes 3-6 weeks — some horses develop persistent carriage without clinical signs
Vaccination reduces disease severity and outbreak risk significantly
Biosecurity during outbreaks requires strict isolation, environmental decontamination, and diagnostic testing
Bastard strangles — internal abscess formation — is a rare but life-threatening complication

Welfare Considerations

Strangles causes significant suffering — fever, painful swelling, nasal discharge, and difficulty eating and breathing during active infection. Horses with severe cases cannot eat or drink normally and may require hospitalisation. The disease spreads rapidly through yards, causing welfare harm to multiple horses simultaneously. Welfare-centred strangles prevention uses vaccination for horses in mixed populations, quarantine of new arrivals for 3 weeks, and rapid isolation at first clinical signs. Horses that have recovered may become persistent carriers and should be tested before returning to group yards. Clear communication between yards about disease status prevents the silent spread that causes large outbreaks.

What You Can Do

Vaccinate horses at risk of strangles exposure — livery yards and competitive horses benefit most
Quarantine all new horse arrivals for 3 weeks before introducing to the main population
Isolate horses immediately if strangles is suspected and inform other yards in the contact network
Test recovered horses for carrier status before returning to group management
Decontaminate equipment, vehicles, and facilities thoroughly after outbreaks