Horse Disease: Strangles

Strangles is a bacteria that impacts equine (horses, donkeys and mules). This ALIRT was initially issued for Maricopa County in January 2022. 

Images below show strangle symptoms including swollen mandibular lymph node (left), open abscesses (middle) and healing absecess (right). Note that flies can transfer bacteria between horses. 

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It is spread both directly (horse to horse, pus or nasal discharge) and indirectly (through contaminated and shared feed/water buckets, grooming tools, fencing, tack, and even people caring for multiple horses). In the case of bastard strangles, which is much more rare, the bacteria can form abscesses internally (on organs). Clinical signs of sickness start after 3 to 14 days from exposure. Recovered horses may shed the bacteria for up to 6 weeks. It is highly contagious and can spread quickly from horse to horse.

These can vary from horse to horse. Early signs include early onset of fever (over 100.5 F in adults, over 101.5 F in foals), mild cough, sluggish, reduced appetite and clear nasal discharge. More advanced signs include wheezing and coughing, thicker nasal discharge that is white or yellow, difficulty swallowing from inflammation of the throat, swelling (externally) from abscesses (internally) forming in the lymph nodes (throatlatch and below the jaw). In rare cases, there may be red spots
on the horse's gums (purpura hemorrhagica) , and swelling of the head, legs, or muscles.

Diagnosis is confirmed through culturing swabs of nasal mucus or abscess pus, or through blood work.

Immediately isolate sick horse(s) from other horses. Monitor the temperature of all horses on property, and isolate horses that develop fevers. Provide supportive care including keeping the horse dry and protected, and provide a soaked and/or easy to swallow feed. Work with your veterinarian for appropriate treatment for your horse.

Full recovery is up to 4 weeks if treated by veterinarian protocols. It is rarely fatal.

Practice good biosecurity techniques such as quarantining sick animals, not sharing feed buckets, stalls and tack with other horses. Feed sick horses last. Clean, remove, and/or sanitize all soiled bedding. Ensure cross contamination is not occurring between horses or handlers. Discuss vaccination options with your veterinarian. 

Note that strangles is a reportable disease because it can not only effect your horse, but the health of the horses around you.