Urolithiasis - commonly known as bladder stones, is a painful condition that occurs in the urinary bladder.  With proper nutrition and treatment, your dog can live without the discomfort of bladder stones.

How are bladder stones formed?

Bladder stones are formed in the urinary bladder, in part due to changes in the pH of the urine, typically caused by urinary tract infection, and also from the presence of excess protein, calcium, phosphorus or magnesium.  The most common types of bladder stones in dogs are struvite, calcium oxalate and urate.

Urolithiasis may be related to the type of food your dog currently eats, but some dogs are simply more prone to stone formation than others because of their individual chemistry and/or breed, i.e., small breeds.  Drinking plenty of fresh water daily or eating canned food can help decrease the likelihood of stone formation

Signs of Urolithiasis

• Inability to urinate, sometimes confused with constipation (contact your veterinarian if you are unsure)
• Difficult, slow urination
• Pain when urinating or inappropriate urination
• Frequent attempts to urinate
• Abdominal discomfort or vomiting
• Incontinence
• Blood in the urine

Course of Action

Depending on the type and number of stones, your veterinarian may recommend a combination of several options.  If your pet has struvite bladder stones, your veterinarian may decide to dissolve them with a therapeutic food.  Once the stones have been dissolved, the next step is a food designed to prevent the recurrence by reducing excess minerals in the urine and creating a more acidic urine.

Antibiotics are often recommended to combat urinary tract infection, and in cases of calcium oxalate or urate stones, surgical removal may be necessary.  Your veterinarian will discuss the best course of action with you.

Home Care

• Watch for signs of recurrence
• Follow your veterinarian's instructions carefully for feeding and medicating your pet.
• Speak to your veterinarian before changing your pet's medication or feeding regimen.
• Provide free access to fresh, clean water

Kinds of Bladder Stones

• struvite - very common in female dogs that are 1-8 years old.  Common breeds are the Miniature Schnauzer, Miniature Poodle, Bichon Frise, and Cocker Spaniel.  Struvites are also seen in both male and female cats.  Struvites form in neutral to basic urine.  Most dogs with struvites have a urinary tract infection caused by bacteria that make the urine more basic.  Most cats have urine without bacteria in it.

• Calcium Oxalate - This is the second most prevalent type of urolith after struvite, making up around 30-50% of diagnosed uroliths, especially in male dogs of most breeds.  They come in two versions; the monohydrate and the dihydrate.  Sometimes the two are found together, sometimes they are found with other uroliths like calcium phosphate, struvite, or ammonium urate.  These are found most commonly in older male dogs, of which several breeds are prone: Schnauzer, Lhasa Apso, Yorkshire terrier, Bichon Frise, Shih Tzu, and Miniature Poodle.

• Urate and Ammonium Urate - This is a common urolith found in Dalmatians around middle age, with males affected much more often than females.  This is because they metabolize protein differently in the liver, with the end result being uric acid buildup in the urine.  In addition to their high prevalence in Dalmatians, they are found in Bulldogs and Yorkshire Terriers.

• Miscellaneous Uroliths - There are other uroliths that occur, although they are relatively uncommon.  They include cysteine, silica, calcium phosphate, and miscellaneous minerals

Feeding Recommendations

Your veterinarian may recommend feeding your dog a product with restricted amounts of certain nutrients, such as magnesium, phosphorus, protein, or calcium to help dissolve and prevent the recurrence of stones.