Today’s video is about uric acid bladder stones in dogs. There are actually several types of bladder stones, but I want to stick to just one type, uric acid bladder stones, also known as urate stones. (Uric acid and urate are the same thing.)
Which Dogs Get Uric Acid Bladder Stones?
There are two primary reasons why dogs form this particular type of stone:
- There is a genetic predisposition. Eighty percent of dogs with urate stones are Dalmatians because this breed is genetically inclined to develop them. Bulldogs and Russian Terriers can also be genetically predisposed to the condition.
There is a DNA test available that can tell you if your dog is carrying one copy or two copies of the gene that contributes to the formation of urate stones. Dogs with two copies of this gene carry the dominant gene and are automatically predisposed. That’s important information to have, especially if your dog is one of the high risk breeds.
- The second reason for development of uric acid bladder stones is the presence of a liver shunt in a dog. If your dog has a liver shunt, you should proactively perform urine checks for urate crystals. This is an important step in preventing stones from forming from urate crystals.
How Urate Stones Form
In order to understand how these stones form, you need to understand a bit about physiology.
Urate stones can form from foods that contain purines. Purines are natural substances found in high concentrations in meat and meat products. Purines break down in the liver into uric acid.
Metabolic processes performed by the liver cells convert uric acid to a water-soluble substance called allantoin. Allantoin is then passed from the kidneys to the bladder and out of the body in urine. This is the physiologic process that takes place in a normal, fully functional body.
In Dalmatians and other breeds predisposed to uric acid bladder stones, the last step in the process doesn’t take place.
Purines are broken down into uric acid, but the uric acid is not converted to allantoin. The ‘untreated’ uric acid passes into the kidneys and on into the bladder. Because it is not water soluble, uric acid crystals can accumulate in the kidneys and move into the bladder. When these crystals cohere, a stone forms.
Urate stones can be a medical emergency for your pet, because if they grow large enough they can block the flow of urine entirely. The inability to pass urine is a life-threatening situation.
Crystals can be very irritating to your dog’s kidneys and bladder and can precipitate urinary tract infections. Symptoms of possible uric acid crystals or a stone include:
- Straining and/or discomfort during urination
- Blood in the urine
- Passing only small amounts of urine
- Urine leakage accidents around your home
- Drinking and urinating more
If you have a Dalmatian or other high risk breed and suspect your pet may have crystals or stones, it’s important to ask your veterinarian to do a urine sample immediately to check for signs of a problem.
Urinary blockage is a medical emergency, but it your dog has crystals or a stone that isn’t completely occluding the urethra, making it impossible to pass urine, the situation can often be managed with medication and dietary adjustments.
The Importance of a Neutral Urine pH
The first goal in managing uric acid crystals or stones is to dilute the urine.
The second goal is to create a neutral urine pH, neither too acidic nor too alkaline. We want to get the urine pH to 7.
In my practice, I recommend owners purchase pH strips at the local drug store and check their dog’s urine pH at home to keep it balanced at 7. This is a great way to be proactive in helping to prevent crystals and stones from ever forming.
It’s best if you can hold a strip into the stream as your dog urinates, but you can also collect it and dip the pH strip in the sample. Just make sure to test the sample immediately to insure the accuracy of the reading. Always check pH in the morning, before breakfast. Checking after meals isn’t accurate as pH naturally shifts after food intake.
Urate crystals are found naturally in the urine of Dalmatians, so just because your Dalmatian has these crystals doesn’t mean he’ll automatically develop a bladder stone. However, in any other breed of dog, urate crystals in the urine are not normal and should be addressed immediately.
Prevention and Treatment
Dogs predisposed to develop uric acid crystals or stones should eat a low-purine diet, preferably raw or at least canned for increased water content in the food.
They should also avoid food, snacks and treats with high vitamin C content. Vitamin C acidifies the urine and can precipitate the formation of urate crystals and stones.
Also to be avoided:
- Brewer’s yeast
In addition to checking your pet’s urine pH at home regularly, if your dog has a liver shunt or you’re concerned about your Dalmatian or other high-risk breed, get a urinalysis at least yearly.
This will allow your vet to check for urine sediment and determine if crystals are present. If they are, you can address the situation immediately with dietary modifications that will reduce the likelihood bladder stones will develop.