Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Seroma, Generally


An injury like a kick to an area may damage blood vessels enough to cause them to leak the liquid part of the blood out, but not badly enough to allow the blood cells out into the area.

This accumulation of plasma or serum in an area is called a seroma. It is essentially a bruise in which there is free liquid (amber-colored serum) within the swelling. When the blood cells leak out into an area, a hematoma is formed.

The division between hematoma and seroma is a blurry line. A hematoma turns into a seroma as a blood clot forms and separates from the serum in the swelling. In time, most seromas are resorbed by the body, but they may leave scars, swelling and blemishes. For this reason, treatment of seromas is sometimes needed, and may require drainage.

The most common area for seroma or hematoma to occur on a horse is the upper limb, chest, stifle area, hamstring area of the rear limb, and abdomen but they can form anywhere.

my vet's role


The prognosis is very good, provided there is no involvement of critical structures.

If large seromas are left alone, the pressure from the fluid within them can cause damage to the underlying muscle, creating a blemish and in rare cases, a mechanical deficit in movement (fibrotic myopathy).

Author: Doug Thal DVM Dipl. ABVP