You may have noticed the tell-tale signs of bladder stones in your pet, such as frequent needing to pee, or even blood in their urine. Or perhaps your dog or cat seemed completely healthy, but the bladder stones were discovered during a routine checkup. Either way, you’re probably wondering what these things are and just how did they come about.

Understanding bladder stones

Also known as uroliths or calculi, bladder stones are rock-like deposits that form in the urinary bladder of dogs, cats and other animals (including humans). These deposits are the result of crystals that form in the urine from a number of different minerals, the most common being calcium oxalate and struvite. Starting as microscopic crystals, these minerals collect over a period of weeks to months to create single or multiple stones that can be anywhere from several millimeters to up to four inches in diameter.

As the stones grow, they will rub against the bladder walls, causing irritation, pain, and blood in the urine. This irritation can also cause inflammation of the bladder walls, making it more difficult for your dog or cat to urinate, but also making the animal need to urinate more frequently. If left untreated, the bladder stones can block the urethra, which becomes a life-threatening situation.

Causes of bladder stones

Though we know exactly how bladder stones develop, it is not always easy to determine exactly what has triggered the growth of these deposits. There are a number of factors that can be involved, including infection, genetic disposition, and an imbalance of the urine content.

Bladder stones in dogs may occur due to a bacterial infection, genetic predisposition, or an imbalance in your dog’s urine pH (either too acidic or too alkaline). These different factors will cause the growth of one or more minerals in particular.

Urinary tract infection – a bacterial infection causes a pH imbalance of the urine, creating a better environment for the growth of crystals. Some bacteria also create an enzyme known as urease, which stimulates crystal growth. This link between infection and bladder stones is prevalent in dogs than in cats.

Dehydration – this causes more concentrated urine and a more acidic pH level, which makes it more likely that crystals will form. Dehydration also means it is harder for the animal’s body to naturally eliminate any crystals that do form.

High mineral levels – if the concentration of these particular minerals is higher, to begin with, it is more likely that crystals, and eventually stones, will form. The reasons for this are usually related to diet, but can also be caused by medications or supplements, or an issue with the animal’s metabolism.

Certain breeds – among dogs this includes Bichon Frise, Yorkshire terriers, Shih Tzus, Dalmatians, dachshunds, miniature poodles, and miniature schnauzers. Among cats, this includes Siamese, Burmese, Himalayan, and Manx. Within these breeds, some are more prone to stones of a particular mineral.