Kidney stones in dogs are rare. But in the bladder - often. Such stones can pass into the urethra. Stones in the bladder can form in all dogs. The rocks that belong to the high risk group are the dwarf schnauzer, Dalmatians, Shih Tzu, Dachshund and Bulldog.
Stones in the bladder and urethra can be large or small, single or multiple, and can spontaneously exit or cover the lower parts of the urinary tract. In addition, stones in the bladder can cause painful urination and the appearance of blood in the urine.
Most of the stones of the bladder are struvites, that is, they consist of phosphoric acid magnesia and ammonia. They are formed in alkaline urine, and this process is usually preceded by infection of the bladder. Bacteria and sedimentary components of urine form a source around which ammonium phosphate is deposited.
Stones consisting of uric acid are formed in acid urine and are often associated with an inborn violation of urate metabolism. Such a genetic predisposition has Dalmatians and Bulldogs.
Other stones may contain calcium oxalate or cystine. Crystals of cystine were found in Newfoundland and many other breeds of dogs. In order to determine the predisposition or carriers of stones, there are genetic tests. Silicon stones are rare, most often in German male shepherds. These stones are usually not associated with a previous infection of the bladder.
Stones that are large or multiple, can sometimes be probed through the abdomen. In most cases, the diagnosis is established based on the results of an X-ray examination. Stones that are not visible when radiographing the abdominal cavity can often be seen during an ultrasound examination or intravenous pyelography. Also, the results of urine tests are taken into account.
Stones that came out on their own or were surgically removed, if possible, should be analyzed, as the composition of the stones affects the treatment of the remaining or future stones.
Treatment: if there is an infectious process in the bladder, it should be treated as described for cystitis. In many cases, stones can dissolve within a few weeks or months if the dog is fed on a special diet. Struvite stones dissolve in acidic urine requiring a diet low in magnesium and protein in combination with a specially formulated food to treat these problems, for example, Royal Canin Urinary SO 13. Stones containing uric acid respond to treatment with a low purine diet in combination with the use of the preparation of allopurinol. Cystine stones are treated with the same diet in combination with drugs that dissolve cystine. Feeding a dog on a vegetarian diet, for example, Royal Canin Vegetarian Formula, can help prevent the formation of urate stones. Techniques that allow the dissolution of stones consisting of calcium oxalate and silicon have not yet been developed. However, diet and nutritional supplements can help reduce the risk of their reappearance.
For the treatment of stones in the urethra, which can cause blockage, and for the treatment of stones in the bladder that have not responded to changing diets and the use of medicines, the approach of choice is surgical removal. Also, this method of treatment can be resorted to if medication is contraindicated because of congestive heart failure or when it is necessary to quickly relieve symptoms.
The formation of new stones occurs in approximately 30% of cases. The dog should be inspected regularly by a veterinarian. He or she can recommend long-term dietary changes and / or nutritional supplements, such as vitamin C, raspberry extract or cranberry extract.