FieldDxStranglesClinical signs, differential diagnosis, treatment and prevention in horses.
Overview
A highly contagious bacterial disease of horses causing abscesses in the upper respiratory lymph tissue. Streptococcus equi subsp. equi. Marked urgent in FieldDx. Zoonotic: this condition can pass to people.
Clinical signs
- Fever first, followed within 24-48 hours by mucopurulent nasal discharge, depression, and swollen lymph nodes under the jaw.
- Retropharyngeal lymph node involvement causes difficulty swallowing, noisy inhalation, and an extended head/neck posture ("strangles" stance).
Predisposing factors
- Streptococcus equi subsp. equi; highly contagious via direct contact and contaminated objects; incubation 3-14 days; some recovered horses become asymptomatic carriers.
Look-alikes to rule out
Equine Infectious Anemia (EIA) Equine Infectious Anemia (EIA / Swamp Fever) Equine Viral Arteritis
Treatment
Supportive care; abscesses may need lancing/drainage. Antibiotics are controversial in uncomplicated cases as they can prolong the carrier state.
Prevention
Isolate new/returning horses, vaccination where available, disinfect shared equipment.
Source
MSD Veterinary Manual — Strangles (Distemper) in Horses (accessed 2026-08-11)
A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs and Goat by ELSEVIER — Strangles
Condensed and attributed, never reproduced whole. Open the full entry in the app.