Only one common type of bladder stone in dogs can be dissolved without surgery: struvite stones. These make up roughly half of all canine bladder stones and respond well to a combination of a prescription dissolution diet and antibiotics. Other stone types, most notably calcium oxalate, cannot be dissolved and require physical removal.
Knowing which type of stone your dog has is the critical first step, because the treatment paths are completely different.
Why Struvite Stones Can Be Dissolved
Struvite stones are made of magnesium, ammonium, and phosphate. In dogs, they almost always form because of a urinary tract infection caused by specific bacteria that produce an enzyme called urease. This enzyme makes the urine more alkaline and concentrated, creating conditions where struvite crystals clump together and grow into organized stones. Bacteria actually get trapped between layers of the stone as it enlarges.
Dissolving these stones works by reversing those conditions. A prescription diet restricts magnesium and phosphorus while lowering urinary pH, making the environment hostile to the crystals. At the same time, antibiotics eliminate the infection that caused the problem in the first place. Without treating both, dissolution typically fails. As Cornell’s veterinary college notes, dietary therapy alone won’t work if the underlying UTI isn’t properly addressed, or if the stones turn out to be a mixed composition.
What the Dissolution Process Looks Like
Your vet will confirm struvite stones through imaging (X-rays or ultrasound) and a urine culture to identify the specific bacteria involved. From there, the two-pronged approach begins.
The dietary component involves feeding a struvite dissolution food exclusively. Brands like Hill’s c/d Multicare are commonly used. Canned versions of these foods may shorten dissolution time compared to dry formulas, largely because they contain more water, which helps dilute urine. Your dog should eat nothing else during this period: no treats, no table scraps, no other foods that could raise mineral levels or shift urine pH back toward alkaline.
The antibiotic component runs alongside the diet. The specific antibiotic depends on which bacteria the culture identifies. Traditionally, vets have continued both the diet and antibiotics for 2 to 4 weeks past the point where imaging shows the stones are gone. More recent thinking suggests a shorter antibiotic course may be just as effective, though your vet will make that call based on your dog’s situation.
Dissolution typically takes several weeks to a few months depending on stone size and number. Your vet will schedule periodic imaging, usually every few weeks, to track whether the stones are shrinking. If they’re not getting smaller after a reasonable period, the stones may not be pure struvite, and surgical removal becomes the better option.
The Role of Water Intake
Increasing your dog’s water consumption is one of the simplest and most effective parts of the process. More water means more dilute urine, which reduces the concentration of stone-forming minerals and makes it harder for crystals to stick together. The Minnesota Urolith Center recommends targeting a urine specific gravity below 1.020 for dogs. If your dog’s urine is more concentrated than that, they need more water.
Practical ways to boost intake include adding water to dry food (or switching to canned), placing multiple water bowls around the house, using a pet water fountain, and flavoring water with a small amount of low-sodium broth. These same strategies help prevent recurrence after the stones are gone.
Stone Types That Cannot Be Dissolved
Calcium oxalate stones are the other major type seen in dogs, and they do not respond to dietary dissolution. Their chemical structure is resistant to changes in urine pH or mineral content. If your dog has calcium oxalate stones, the options are surgical removal, a minimally invasive procedure called cystoscopy (where small stones are retrieved through the urethra), or lithotripsy (where shock waves break stones into passable fragments). After removal, diet and hydration changes focus on preventing new stones from forming.
Less Common Dissolvable Stones
Urate Stones
Urate stones, which are more common in Dalmatians and dogs with liver shunts, can sometimes be dissolved or managed medically. Treatment typically involves a low-purine diet combined with a medication that reduces uric acid production. These stones are less common than struvite or calcium oxalate but worth identifying because they do have a non-surgical path in many cases.
Cystine Stones
Cystine stones are rare and tied to a genetic defect in how the kidneys handle certain amino acids. Dissolution involves multiple strategies layered together. Prescription diets help, and potassium citrate can be used to raise urine pH into the 7 to 8 range, which increases cystine’s solubility. For dogs with repeated episodes, chelating medications that bind to cystine and make it more soluble may be added. In male dogs whose cystine stones are driven by hormones, neutering alone can sometimes resolve the problem, though combining it with dietary therapy and chelation speeds things up considerably.
Risks During Dissolution
One important consideration during medical dissolution is that as stones shrink, smaller fragments can break off and travel into the urethra. In male dogs especially, whose urethra is longer and narrower, this can cause a partial or complete blockage. A urethral obstruction is a veterinary emergency: signs include straining to urinate, producing only drops, crying out, or being completely unable to pass urine. If you notice any of these during the dissolution process, your dog needs immediate veterinary attention.
This risk is one reason vets monitor dissolution with regular imaging rather than simply prescribing a diet and checking back months later. Catching a lodged fragment early prevents a straightforward process from turning into an urgent one.
Why Identifying Stone Type Matters First
Bladder stones in dogs all look similar on X-rays. The only reliable way to know what they’re made of is mineral analysis, which requires either retrieving a stone (surgically or through the urethra) or, in some cases, making an educated guess based on urine crystals, bacterial culture, breed, and imaging characteristics. Some vets will attempt a dissolution trial for suspected struvite stones and monitor with imaging. If the stones aren’t shrinking within a few weeks, that’s a strong signal the composition is something else.
Attempting to dissolve a calcium oxalate stone with a struvite diet wastes time and prolongs your dog’s discomfort. Getting the stone type right, or at least having a confident working diagnosis, is what makes the difference between a treatment that works and weeks of frustration.