Distilling The Facts About Horses' Kidneys

Distilling the facts about kidneys

Your horse’s kidneys do a phenomenal job, processing around 45 litres of blood twice each hour, to filter out waste and retain all the important bits your horse needs to stay healthy.

Where are the kidneys?

Like all vertebrate mammals horses have two kidneys. They are situated just behind the saddle area, within the abdominal cavity beneath the last ribs, one either side of the lumbar part of the spine. The left kidney sits slightly further back than the right and it is possible for your vet to feel the edge of it during an internal examination.

What do the kidneys do?

The kidneys are a major part of your horse’s urinary system, responsible for the extraction and removal of waste products from the blood.

Each kidney weighs on average around 680g but the right kidney is shaped like the heart on a playing card whereas the left is a more conventional kidney shape.

Contained within their own capsules, the kidneys are surrounded by a protective layer of fat and a substantial layer of muscle. A drainage tube, the ureter, runs to the bladder from each kidney and both are connected to the circulatory system via a renal vein and renal artery.

Waste processing and purification

The kidneys process the blood to remove any harmful or unnecessary waste products generated from bodily activity.

The blood is processed in two layers of tissue, where more than a million microscopic nephrons purify incoming fluid. Salt, potassium, sulphate, phosphate, glucose and proteins are released back into the