Bladder stones and obstructions
Bladder stones are rock-like accumulations of minerals which can form in the bladder, they can occur as a few larger stones or multiple smaller stones. The smaller stones can sometimes block the urethra, which is the outflow tube from the bladder, causing pain or difficulty with urination. The larger stones can be rough and traumatize the lining of the baldder causing pain, bleeding and bladder infections.
Signs of bladder stones
Depending on the size and number of stones that form in the bladder, sometimes pets do not show any signs of having them. In other cases, the presence of bladder stones can cause blood-tinged urine, difficulty urinating and increased frequency of urination. If the stones are blocking the urethra preventing urination, this can quickly become painful for the pet, and they may appear lethargic, lose their appetite and can often vomit.
If the bladder cannot empty urine, not only is this painful for the pet, but the pressure that builds will also cause severe damage to the kidneys. A blocked bladder is an acute, life threatening problem as the bladder when stretched, can be at risk of rupturing causing urine to leak into the abdominal cavity.
Why do bladder stones form?
There are a few reasons that contribute to the formation of bladder stones, the main two being excessive levels of particular minerals excreted in the urine, and changes in urine pH, which refers to how acidic or alkaline the urine is.
Bacterial infections are another cause because they alter urine pH, in certain breeds like Dalmations, a genetic problem can lead to abnormal metabolism of various minerals.
Some of the common minerals that make up bladder stones include, magnesium, sodium, oxalate, phosphorus and calcium.
Some foods and diets may contain excessive amounts of certain minerals, which will then be excreted into the urine. There are a few breeds of dogs who have trouble processing these minerals and safely excreting them, which causes a build up.
Diagnosis of bladder stones usually involves imaging of the bladder, with an X-ray or ultrasound. Sometimes smaller stones can be visible when the urine is tested.
Treatment of bladder stones will vary depending on the size of the stones and the type of mineral which has formed them.
Larger bladder stones in the bladder or lots of smaller stones that are causing damage need to be surgicaly removed.
In cases where the stone may have passed from the bladder into the urethra causing a blockage, a catheter is used to flush the stone and relieve the blockage.
In many cases bladder stones tend to reoccurr, and ongoing management is a vital part of reducing the risk of stones reforming.
Diet is the best way we can manage the amount of minerals that are excreted into the urine, which in turn will reduce the chance of stones forming.
For example some pets are fed too many human foods that contain high oxalate levels, such as green veggies like spinach and silver beat, and other foods like potatoes and beans.
As for cats, many cat foods cause the urine to become too alkaline, which in turn results in the formation of struvite crystals, a common cause for bladder blockages.
There are several prescription diets which are scientifically designed to reduced the minerals, and maintain a healthy urine pH. Some of these diets can also help to dissolve smaller stones in the early stages.
For pets with a history of bladder stones regular urine tests can also be an important way of knowing if they are at risk of stones reforming.
Bladder stones in general can be very well managed, but does require an appropriate treatment plan that is followed consistently.