Joint and tendon sheath infections are a very common occurrence in horses and ponies. Most happen when bacteria enter the joint space through a wound. They can also occur when an infection enters the joint through circulating bacteria in the blood. This happens especially in foals.

Horses with an infected joint or tendon sheath tend to be in a lot of pain and often do not put weight on the leg. The area is usually very swollen and synovial fluid might even be seen coming out of the wound.  Horses would normally start developing a fever, and are reluctant to eat.

There are several ways a vet can confirm whether a joint has been penetrated. These include:

  • Detection of joint fluid emerging from the wound on examination.
  • Injecting the potential synovial structures involved with sterilesaline and seeing whether this fluid exits the wound.
  • Collection and analysis of a sample of fluid taken from the joint. This is the most accurate method. Submitted samples are analysed for the number of white blood cells present, the proportion of these that are neutrophils (the white blood cells responsible for attacking bacteria), the protein level and the presence of bacteria. All these values are increased in horses suffering from an infected joint.
  • X-rays and/or ultrasound scanning may occasionally be helpful.Treatment should be started as soon as possible following



  • Remove / destroy the bacteria causing the infection
  • Remove any foreign materials such as sand, hair and dirt
  • Prevent cartilage damage by removing destructive enzymes
  • Control the spread of infection to adjacent parts of the body

Lavage (flushing) of infected structures and antibiotics are the treatment of choice. Lavage should ideally be carried out by arthroscopy (keyhole surgery). This technique allow for large volumes of sterile fluid to be flushed through the structure, it also allows for a visual evaluation of the joint or tendon sheath and removal of infected tissue and foreign bodies. Rather than surgical lavage, occasionally joints or tendon sheaths can be flushed through needles, however this is usually less successful. Antibiotics may be given intravenously or intramuscularly as well as in and around the joints by regional limb perfusion.

Horses are then monitored for several days; They are checked for lameness and several samples of synovial fluid are taken  for evaluation.

If the infection is recognised and treated early in a proper way then the horse has a good chance of full recovery.

You should always consult with a vet when a wound is close to a joint or a joint swelling is observed.

At Vets On Wheels Clinic in Marsa we have an on-site lab and surgery that allow for a quick and early diagnosis, as well as targeted treatment, maximising the possibility of your horse returning to full athletic performance.  (see similar story of Lemon published in a previous blog) 

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