Infection of the Shoulder in Horses

A shoulder infection can mimic problems such as arthritis, bursitis, fractures, sprains, and foot wounds.

Your horse may present with typical symptoms of infection such as fever, heat at the site of the infection, pain, discomfort or altered gait. The veterinarian will need to be contacted for an evaluation as an infection can quickly become a problem if left untreated. Treatment could include a simple course of antibiotics or may involve surgery to clean and disinfect the area.

Infections of your horse’s shoulders and joints are rare and at times difficult to diagnosis. These infections may or may not cause symptoms in your horse. 

The symptoms may be generalized or more specific. 

• Heat – There may be heat at the site of a wound or other areas of his body when touched 
• Swelling/inflammation – There may be noticeable inflammation of his shoulder or other joints where the infection is present 
• Noticeable wounds – You may see a wound at the site of the infection
• His stance – Your horse may be favoring one side of his body or leg more so than the other or avoiding use of the injured shoulder 
• Swinging leg – He appears to be in pain when trying to move his leg
• Fever – Within 8 to 24 hours of infection setting in, your horse may develop a fever

There are a few possible causes of shoulder infection in your horse including bacteria from somewhere else in the body invading the blood, trauma, and infection introduced during other treatment. 

Bacteria

• This is known as infectious or septic arthritis
• Caused by bacteria from other areas of your horse’s body traveling through his bloodstream to his joints and causing infection
• This can lead to permanent damage if left untreated
• Destroys cartilage in his joints
• The bacteria travel from the navel, gut or lungs typically 

Trauma

• If your horse develops an injury at his joint this can cause infection

Other Treatment

• Infection can be introduced if your horse is undergoing other procedures on his joints/shoulders
• Due to opening your horse’s body there is chance of exposure to possible foreign bacteria
• In addition, certain medications cause a high risk of introducing infection due to decreasing the joint’s typical ability to fight off infection

Diagnosing a shoulder infection can be difficult to do due to lack of symptoms. Should you suspect there is something wrong with your horse’s shoulder including possible infection, contact the veterinarian for an evaluation. A physical exam of your horse will be done to look for obvious trauma, injury, or inflammation.

Your horse may also be checked for a fever and fluids may be drawn. These include joint fluid to check for infection. This fluid will be sent for cultures for bacteria. Blood work is another tool used for diagnosing infection and may indicate sepsis and show changes in the cell count. Imaging tools can be used as well; ultrasound and x-rays, are used in the event the joint is open and no fluid can be drawn to culture for infection. In some instances, throughout treatment, x-rays will be used to monitor the infection.

Once your veterinarian identifies the cause of your horse’s shoulder concerns, treatment will commence immediately. Infections are typically treated with antimicrobials. Sometimes this medication can be administered directly to the site of the infection. 

If this line of treatment does not work, the next step can be surgery to remove debris and clean the infected area. This surgical technique is called arthroscopy and is the most commonly used surgical procedure for shoulder infections. Your horse’s shoulder may also be flushed in order to clean and sterilize the area and anti-inflammatory treatments can be provided as well. In cases of deep infection or infection that has advanced to a critical stage, hospitalization may be required to give supportive care, such as intravenous antibiotics and pain relief.

Follow up will be necessary. It will be important to keep the wounds clean and restrict your horse from partaking in strenuous activity while his shoulder continues to heal. Recovery is guarded for shoulder infections especially in foals, however, in adults the prognosis of recovery is much higher. Foals that are treated within 2 days of symptoms beginning have the best long term survival rate.