Horse Strangles: Managing a Painful Bacterial Disease

Strangles is a highly contagious bacterial infection in horses causing painful abscess formation in lymph nodes. Biosecurity and vaccination are essential welfare tools.

Key Facts

Strangles is caused by Streptococcus equi subspecies equi — one of the most infectious horse diseases
Infection causes fever, nasal discharge, and dramatic swelling of lymph nodes under the jaw
Abscesses rupture spontaneously, releasing large volumes of highly infectious pus
Spread occurs through direct contact and contaminated water, troughs, and equipment
Bastard strangles (spread to internal lymph nodes) causes severe chronic disease and is often fatal
A live attenuated intranasal vaccine is available but has limitations and cannot be used in all horses

Welfare Considerations

Strangles causes significant pain through fever, swollen abscesses pressing on the throat (causing swallowing difficulty and the "strangling" sensation), and abscess rupture. Affected horses show reduced eating, lethargy, and clear signs of distress. Treatment is primarily supportive — ensuring abscesses drain properly, providing soft food, and monitoring for complications. Antibiotics are controversial as they may prevent abscess maturation. Biosecurity isolation of affected horses is critical to limit spread and prevent additional animals from suffering.

What You Can Do

Implement biosecurity quarantine immediately if strangles is suspected in your yard
Hot-poultice developing abscesses to encourage maturation and drainage
Provide soft, soaked feed to horses having difficulty swallowing due to swollen lymph nodes
Work with your vet on a vaccination strategy appropriate for your yard's risk level