Beating The Bulge

A sudden and dramatic swelling could be a bleed into the body tissues, called a haematoma. Gil Riley MRCVS outlines treatment options

ACCIDENTS happen, especially where horses are concerned, so it’s not uncommon for trauma and bruising to occur through a kick, a fall or a collision with an object such as a gatepost. As a result, we can suddenly discover a large, soft lump on some part of the horse’s body — typically the hindquarters, chest or ribs.

The skin might not be broken but one or more of the blood vessels beneath are damaged and bleeding. This blood can fill the space between the damaged tissue and the overlying skin, forming a swelling called a haematoma. The swelling will grow until the pressure that builds up from the fluid accumulation halts the bleeding, allowing a clot to form in the ruptured vessel. Blood pressure is, therefore, an important factor in determining the eventual growth and size of the haematoma.

Since arteries have a higher blood pressure than veins, the haematoma caused by the rupture of an artery will be larger — until sufficient back pressure develops to stop the artery losing blood. If the haematoma continues to expand and is not being confined to a limited area, your vet may advise an operation to identify the haemorrhaging vessel and ligate it (tie it off).

Most of the time, haematomas are best left alone to resorb (absorb again) — a process that can take weeks or even months. Sometimes, however, your vet will drain the swelling, a decision that will depend on how big it is, how long it has been there and whether the growth is interfering with the horse’s ability to move.