Hematomas in Horses

Your young gelding has been play-fighting with his pasture buddies and comes in with a big swollen spot on his hindquarters. It feels just slightly warmer than the rest of the horse’s skin and is at least as big as your fist, but there’s no cut or bleeding that you can see. What in the world has he done to himself this time?

A hematoma—a soft, blood-filled spot under the skin—occurs as the result of bruising at the location of a kick or other blunt-force trauma. A horse that runs its chest into a tree or fence post may develop a hematoma that can be as big as a football. Horses can also develop a hematoma if they hit a shoulder or hip against the door frame as they enter a stall.

What should you do? Cold hosing can sometimes keep the hematoma from getting bigger, but the bleeding will usually stop on its own, assisted by the pressure of swollen tissues. Though it may sound like a good idea to drain the swollen area, this step doesn’t help in the initial stages and can invite infection to set in.

Check with a veterinarian as to treatment for a very large hematoma. A veterinarian should also examine the horse if the swelling is hot, seems painful, or begins to drain pus. These swellings are likely to be abscesses, possibly from pigeon fever or another infection, and will probably need to be treated right away. Hematomas usually disappear over time without treatment, though it can take several weeks before the area returns to normal.