Urinary stones

What are the causes of urinary stones?

Urinary stones form when the salts dissolved in the urine accumulate to form crystals and these combine to form larger formations. The salts can be calcium, phosphate, magnesium or uric acid, for example. The formation of urinary stones depends on various factors, such as

• The concentration and pH value of the urine
• The composition of the food
• The amount of drinking and urination
• The presence of bacteria or other pathogens in the urinary tract
• The genetic predisposition or breed of the dog

There are various types of urinary stones, which differ in their composition and appearance. The most common are

• Struvite stones: These consist of magnesium, ammonium and phosphate and usually have a smooth surface. They are often associated with bacterial urinary tract infections and are more common in female dogs.
• Calcium oxalate stones: These consist of calcium and oxalic acid and usually have a rough surface. They can be favored by a high calcium intake or a low pH value of the urine. They occur more frequently in male dogs.
• Urate stones: They consist of uric acid and usually have a yellowish color. They can be favored by a high purine intake or a genetic defect. They occur more frequently in certain breeds, such as Dalmatians or Schnauzers.

How do I recognize urinary stones in my dog?

The symptoms of urinary stones can vary depending on the size, number, location and type of stones. Some dogs show no symptoms at all, while others have severe symptoms. The most common symptoms are

• Frequent or difficult urination
• Blood in the urine or discolored urine
• Pain when urinating or in the abdominal region
• Uncleanliness or urinating in unusual places
• Fever, loss of appetite or lethargy

If the stones block the outflow of urine, a life-threatening urinary blockage can occur. This manifests itself as

• Repeated straining without passing urine
• Severe pain and restlessness
• Vomiting or diarrhea
• Shock or coma

If you notice any of these symptoms in your dog, you should see a vet immediately.

How are urinary stones diagnosed and treated?

To diagnose urinary stones in your dog, the vet will perform a physical examination and take a urine sample. The urine sample will be analyzed for bacteria, blood, crystals and other abnormalities. To determine the location, size and number of stones, the vet may also perform an x-ray or ultrasound examination. To determine the type of stones, the vet may also take a sample of the stones or have them analyzed.

The treatment of urinary stones depends on the type, size and location of the stones. The possible treatment options are

• Drug treatment: some stones, such as struvite stones, can be dissolved by administering antibiotics, uric acid-lowering drugs or other substances. However, this can take several weeks or months and requires regular monitoring of the urine.
• Change of diet: Some stones, such as struvite stones or calcium oxalate stones, can be prevented or reduced by adjusting the diet. The vet can recommend a special diet food that changes the pH value of the urine or restricts the absorption of certain minerals. You should also always provide your dog with plenty of fresh water to dilute the urine.
• Surgical removal: Some stones, such as large or numerous calcium oxalate stones, cannot be dissolved with medication and must be removed surgically. This is usually done through an abdominal incision or a minimally invasive method, such as endoscopy. However, the operation also involves risks and requires anesthesia and follow-up care.
• Irrigation: Some stones, such as small or individual urate stones, can be removed by irrigation. This is done by introducing a liquid into the bladder or ureter, which flushes the stones out of the urinary tract. Flushing can be performed under anesthesia or sedation.

How can I prevent urinary stones in my dog?

To reduce the risk of urinary stones in your dog, you should take the following measures:

• Feed your dog a high quality, balanced diet that meets his needs. Avoid too much calcium, phosphorus, magnesium or purine in the food. Follow your vet's recommendations regarding the amount and type of food.
• Make sure your dog always drinks enough fresh water. This helps to dilute the urine and promote the excretion of minerals. Place several water bowls around the house and change the water regularly.
• Encourage your dog to urinate frequently. This will help prevent urine from sitting in the bladder for too long and prevent crystals from forming. Take your dog for a walk at least three times a day and praise him when he urinates.
• Have your dog checked regularly by the vet. This helps to detect and treat possible urinary tract infections or other diseases at an early stage. Have your dog's urine checked at least once a year.