Capped elbow

Veterinary advice should be sought before applying any treatment or vaccine.

Capped Elbow

Shoe Boil, Olecranon Bursitis, Elbow Hygroma

Capped elbow is a soft, fluid-filled swelling that develops just beneath the skin surface over the point of the horse's elbow.
Capped elbow location horses
The swelling can range in size from barely noticeable to the size of a melon. It develops as a result of (usually chronic) trauma to that specific location. Horses often rest on the point of their elbow while laying down, and usually use it as an aid in getting up from laying down. Capped elbow is frequently found in horses that are housed on a hard substrate, such as a stall with little to no bedding substrate. It can also be caused by wearing horseshoes that project beyond the heels.

Early clinical signs of capped elbow in horses may consist of minor skin irritation, with hairless, flaky, and/or thickened skin. Over a period of time, if the repeated trauma continues to occur, the elbow can become infected and form a false bursa---which is a painful, abscess-like swelling that requires surgical drainage by your veterinarian. However, if the swelling has been present for longer than a month, surgical removal of the fibrous sac may be necessary.


Soft, fluid-filled swelling at the point of elbow
Thickened, flaky or hairless skin


  • History
  • Clinical signs
  • Physical exam
  • Laboratory testing



Doughnut boots
Cold water therapy
Drainage of fluid
Corticosteroid injections
Application of udder balm/baby oil


  • Use trailer boots or padded leg wraps when transporting on a trailer.
  • Use commercial shoe boil boots, which consist of thick, rubberized doughnut style rings which are fitted around the horse's pastern, and prevent the heels of the shoe from rubbing up against the point of the elbow when laying down.
  • Make your own shoe boil boot, using 10 to 14 inches (25 to 35 cm) of old stirrup leather with a few holes punched in the end, a couple layers of roll cotton (or an alternative padding material), and duct tape.
  • Provide at least 3 inches thick of bedding substrate for horses on stall floors.

Scientific Research

General Overviews

Risk Factors

  • Horseshoe style - wearing horseshoes that project beyond the heels.
  • Providing horses with little to no bedding substrate to rest on in stalls