What Causes Bladder Stones in Dogs?
It depends on the type. In female dogs, struvite stones are most common and usually follow a bladder infection. Calcium oxalate stones are linked to breed, genetics and urine chemistry, and urate and cystine stones to inherited conditions. Concentrated urine raises the risk of all of them.
Ask your vet what type the removed stones were, since that guides the diet and rechecks needed to stop them returning.
See bladder stones in dogs for each type.
This is general information, not a diagnosis. Please follow your own vet's advice.