Kidney stones in dogs, just like in humans, can be very painful and can lead to serious health issues if not treated. While some breeds may be predisposed to inherit the ability to create kidney stones, there are a certain number of factors that if combined could cause kidney stones to form in any dog. In this article, we'll look at what kidney stones are and how they form, what their symptoms are and how they can be treated.

What are kidney stones?

Dogs, just like humans, naturally have minerals in their bodies, such as calcium, magnesium, ammonia or phosphorus. Where there is too much of these mineral salts in the urine, they are filtered out through the kidneys. Because it can be difficult for these minerals to be soluble in the naturally acidic urine of dogs, these minerals can form stones. While they may not pose a health risk while in the kidneys, they may grow very large and be quite painful if they pass through the rest of the urinary tract, even blocking the tract in the worst cases.

Stones may consist of different types of minerals, and each type of stone is often associated with its own unique cause. Some general causes of kidney stones can include kidney or urinary tract infections, dietary factors, medications, or geriatric affects.

What dogs are at risk?

While kidney stones are somewhat rare among dogs, they do exist and there are some breeds that are naturally predisposed to develop kidney stones, such as Dalmatians, Yorkshire terriers and English Bulldogs. Kidney stones tend to appear more in female dogs and also older male dogs.

Symptoms of kidney stones

Unfortunately, in some cases there are no visible symptoms. Other dogs may have sudden colic or have intermittent bloody urine. The most obvious symptoms will occur if the stones pass into the tubes that lead to the bladder, or the ureters. This will cause severe pain, straining and agitation until the stone passes or is surgically removed.

Diagnosis and Treatment

Most stones are visible on an x-ray. Some stones are made up of more organic matter than mineral and may be more difficult to find on an x-ray, so an ultrasound could be used to locate them.

There are different methods of treatment depending on the size or type of stones found in the kidneys. If they are very large and not likely the pass into the ureters, the stones could be managed through diet. There are diets available commercially that encourage the stones to dissolve. They have less protein, so less ammonia forms in the urine, and more salt to encourage drinking, which can help dilute the urine. Dogs that see no changes in five or six months will probably have the stones removed surgically.

Stones that are in danger of passing through the ureters or have not changed after a change in diet will need to be removed surgically. The stones are removed from the kidney, then the kidney is flushed and sewn up.

In order to help discourage kidney stones from reforming, dogs should have a urine test twice a year to prevent urinary tract infections, have access to urinate frequently and plenty of water to keep them hydrated and the urine well diluted.