Dear Dr. Baum —
Hello, I was wondering if you could answer a question for me? We have a dog who has been eating a very good dog food (all natural, no added chemicals, preservatives or additives, etc.) for the past 8 years, that he also really liked. This past week he was acting very strange…when we took him to the vet, they said he had bladder stones and that he needed surgery (almost $3,000). They had said that is was most likely caused by the food he has been eating, and that things like fat should be avoided. They put him on a “Special Diet,” and the first three ingredients are rice, corn, and chicken fat. They just said the fat was bad, but it’s in their “Special Food.” I was always under the impression that corn was not the best thing for dogs and their digestion. My question is (3 parts): What is the most likely cause of bladder stones? And will their “Special Food” (Royal Cann — Urinary SO 14) stop this from occurring again?
(2) Also, what is the most important part of a dog’s food that would stop or eliminate bladder stones? (Basically, is it certain ingredients, moisture content, protein, fat, fiber, or something else?
(3) And is there less of a chance of bladder stones, in general, or in the future, if his food contained something like lamb or fish instead of beef or chicken?
Thank you in advance for any help you can give!
There is nothing wrong with the food that you had been feeding. The problem is either your dog’s metabolic system or its inability to handle normal food stuffs.
There are several types of bladder stones that occur in dogs. The most common type is called struvite and its formation is due to an inability to effectively eliminate normal dietary amounts of manganese and phosphorous in the presence of an infection in the bladder. This type of stone forms in an alkaline urine. There is a breed predilection of beagles and schnauzers. Surgical removal is the preferred method of removal although in some cases, dietary dissolution of the stones is possible. Diet modification and maintenance of an acidic urine usually prevents recurrence.
Oxalate stones form in acidic urines. This is a genetic disorder that fails to program the individual to produce a certain hormone, nephrocalcin, which allows the oxalates to remain dissolved in the urine. Surgery is the only alternative for removal and recurrence occurs in upwards of 50% of the cases in spite of dietary control and medication to keep the urine alkaline (potassium citrate).
Urate stones are also hereditary and due to failure to produce and enzyme to convert the uric acid into a more dissolvable substance. They form in acid urines. Seen most often in Dalmations and English Bulldogs these stones only be surgically removed and then successfully treated to prevent recurrence by feeding a diet low in certain proteins that maintains an alkaline urine in addition to a medication (allopurinol).
Cystine stones are also genetically mediated and involve a defect in the kidney. They form in acid urine. Surgical removal is the only treatment and 90% of the cases can avoid recurrence through diet and medication (d-penacillamine).