Horse Distemper

Information on the respiratory system and equine distemper (strangles) in horses.

equine distemper (strangles) in horses

Select a Topic

  1. What is Horse Distemper?
  2. What Causes Horse Distemper?
  3. Diagnosing Horse Distemper
  4. Help for Horse Distemper
  5. More Information on Horse Distemper

What is Horse Distemper?

Horse distemper, also known as strangles is a highly contagious upper respiratory disease of horses, mules, donkeys, ponies and zebras.

What Causes Horse Distemper?

Strangles in horses is caused by the bacteria Streptococcus equi which affects the lymph nodes in the upper respiratory tract. The lymph nodes become swollen under the jowl and throatlatch area and cause breathing difficulties for the horse.

The horse makes strangling breathing sounds and this is how the condition "strangles" got its name. This bacterial infection develops as a result of direct contact with infected horses and is also spread through food, water and equipment. Bacteria found in nasal discharge and abscesses of infected horses are very contagious and when they are secreted into the air, they are inhaled by other horses causing them to become infected.

Equine strangles or distemper may affect horses of all ages but horses under the age of 5 years tend to be more susceptible to this disease. Cold and damp weather conditions may also increase the horse’s risk of contracting distemper. Symptoms usually develop two to six days after exposure.

If left untreated, abscessed lymph nodes will develop and rupture and drain. Abscesses that form throughout in the body (lungs, liver, spleen, kidneys and brain) are known as bastard strangles and this form is life threatening. Although distemper is highly contagious, it is seldom fatal.

Diagnosing Horse Distemper

The diagnosis of distemper is based on the symptoms, complete physical examination and review of the horse’s medical history. Certain diagnostic tests such as nasal swabs and culture, and blood tests may be performed to confirm the diagnosis.

The common symptoms and signs of strangles in include:
  • High fever
  • Poor appetite
  • Refusal to drink
  • Depression
  • Watery discharge from nostrils which turns thick and yellow
  • Enlarged upper respiratory lymph nodes – between the jawbone
  • Abscessed lymph glands


Help for Horse Distemper

Horses suffering from distemper should be isolated immediately for at least 4 to 6 weeks before being exposed to other horses. Treatment involves antibiotic therapy, anti-inflammatory medications, intravenous fluids and lancing of abscesses. Hot packs can also be applied to swollen and abscessed lymph nodes to reduce swelling.

Ensure that your horse is vaccinated against strangles – although vaccinated horses may still contract distemper, symptoms and duration of the disease are less severe. Disinfect all water containers, feeders, brushes, plastic boots, gloves, clothing, stall walls, fencing and trailers thoroughly to prevent trouble. Wash hands thoroughly and change clothing after working with horses that are isolated.

More Information on Horse Distemper

Tips to manage horse distemper

Although distemper cannot be prevented, there a number of ways to manage and cope with this infection and these include:

  • Isolate the horse immediately if he has contracted distemper
  • Make sure that your horse’s vaccines are updated regularly
  • Disinfect all brushes, water containers, feeders, buckets, tack and clothing that comes in contact with an infected horse
  • Monitor all horses that are exposed to see if they are they are showing any symptoms of distemper with a fever of 103F.
  • Keep the number of horses on a yard to a minimum as overcrowding can increase infection
  • Limit your horse’s contact with unfamiliar horses to reduce the chance developing distemper
  • Strengthen your horse’s immune system by adding immune-boosting supplements to his diet


  • Click to verify BBB accreditation and to see a BBB report for Silver Star Brands, Inc.
  • McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
  • We accept Visa, Mastercard, American Express, Discover and PayPal
  • One year money back guarantee

All images on this site are property of Silver Star Brands, Inc. and/or the original image licensors. The content of these images is not meant to suggest that the person depicted uses or endorses our products or services. Informational material and representations have been provided by the manufacturers of the listed products. All rights reserved. Copyright © 1997-2015 Silver Star Brands, Inc.