06/07/2026
π¨STRANGLES: What Horse Owners Need to Know
WHAT IT IS
Strangles is a highly contagious bacterial infection caused by Streptococcus equi subspecies equi (S. equi ssp equi). It affects the upper airways and lymph nodes around the head and neck. Note there's a closely related subspecies, S. equi ssp zooepidemicus, which is a different organism and does not cause strangles β so make sure any lab result specifies ssp equi. It spreads easily, but most horses recover fully within 4β6 weeks with good care.
SIGNS TO WATCH FOR
A high temperature is usually the first sign β often before anything else β so take your horse's temperature regularly after travel, events, or contact with new horses. Other signs: lethargy, going off feed, thick yellow nasal discharge, a cough, and swollen lymph nodes under the jaw that may abscess and burst.
Simple rule: fever and a snotty nose after travel or mixing with unfamiliar horses? Treat it as strangles until your vet says otherwise.
IF YOU SUSPECT IT
Isolate first, then call your vet. Keep the affected horse well away from others before doing anything else. Don't assume a horse is clear just because it looks better β they can keep shedding bacteria for weeks. About 1 in 10 recovered horses become silent carriers that look healthy but still infect others, which is why following your vet's testing advice to the end matters.
A WORD ON ANTIBIOTICS
It's important not to reach for antibiotics unless your vet specifically advises them. In most cases they do more harm than good β they can delay abscesses maturing, prolong the illness, and reduce the natural immunity your horse builds. Good nursing care is the mainstay of treatment. Leave the decision to your vet, who will only use antibiotics in specific situations.
PREVENTING SPREAD
New or returning horses: isolate and quarantine for 14β21 days, check temperatures twice daily before mixing as horses are febrile a couple of days before they are infectious.
Don't share gear: buckets, feed bins, grooming kit, tack and halters all carry it.
Clean transport between trips; wash hands between horses.
Watch the water: bacteria survive 4β6 weeks in troughs and over a month in dried discharge. Sunlight, drying and thorough cleaning kill it faster.
VACCINATION
A key defence, especially for travelling horses. Standard NZ course is three doses two weeks apart, then a yearly booster (six-monthly for high-risk horses), often combined with tetanus (e.g. Equivac 2-in-1). Never vaccinate a horse that's currently sick or recently exposed β it can cause serious complications. Take your vet's advice on timing.
MANAGING AN OUTBREAK
Split horses into three groups and keep them apart: infected, exposed, and clean. Use separate gear (ideally separate people) for each, monitor temperatures twice daily, and stop all movement on and off the property until your vet gives the all-clear.
A NOTE ON STIGMA
Strangles carries an unfair reputation that can make people reluctant to report it. Please don't let that stop you β early, open communication protects every horse. Affected owners deserve support, not judgement.
For more information check out the link π
https://www.nzeha.org.nz/strangles
