Bladder Stones in Pets
Just like in humans, dogs are also susceptible to stones forming in their urine. These stones, called uroliths or calculi, generally form in the urinary bladder of both males and females. The size and number of stones can be quite variable. There are several signs that can indicate the formation of urinary calculi, however many patients may be asymptomatic (not showing any). Prevention and monitoring is very important to avoid an emergency blockage or long term kidney disease.
What signs are seen when pets have bladder stones?
The most common signs of bladder stone formation is increasing frequency of urination, straining to urinate and blood in the urine. Affected pets may show all, some, or none of these signs. If the urinary tract becomes blocked by a stone it is an emergency. So if you notice your pet straining with no urine produced is important to seek immediate veterinary advice.
What makes bladder stones form?
There are many types of bladder stones that can form with each having different specific causes. These causes include:
- Excess mineral secretions into urine (such as calcium, magnesium and phosphate).
- Abnormal urine pH
- Bacterial infections (cystitis)
- Abnormal metabolism
The period of time for the stones to form is highly variable. They can form in just a few weeks, or may be months (or even years) before they are noticed.
Are some breeds more likely to get bladder stones?
Although, some breeds have predilections to certain types of bladder stones, it is not certain that they will form that type of stone.
- Struvite : Miniature Schnauzer, Bichon Frise, and Cocker Spaniel.
- Calcium Oxalate : Miniature Schnauzer, Lhasa Apso, Yorkshire Terrier, Miniature Poodle, Shih Tzu, and Bichon Frise
- Urate : Dalmatian and Bulldog
- Cystine : Bulldog, Dachshund, Basset Hound, Chihuahua, Yorkshire Terrier, Irish Terrier, and Newfoundland
- Calcium phosphate : Yorkshire Terrier, Miniature Schnauzer, and Cocker Spaniel
- Silicate : German Shepherd, Golden Retriever, Labrador Retriever, and Miniature Schnauzer
Mixed breed and alternative breeds of dogs are susceptible to form any type of stone.
How are bladder stones diagnosed?
Although bladder stones can sometimes be felt by palpating the abdomen and isolating the bladder, often radiographs (x-rays) and ultrasound is needed to identify their presence. Depending on the type and size of the stone, some diagnostic methods work better than others. Often we are unable to diagnose the type of stone without removal and submission to a commercial laboratory. It is also possible for a pet to have two different types of stones at the same time.
What treatment is available?
Treatment for bladder stones usually requires general anaesthesia and surgery to open the bladder and physically remove the stones. A urine culture is also required to isolate any infection to be appropriately treated.
In rare cases, some types of stones can be dissolved using special diets if the stones are small enough.
Prevention of bladder stones
Generally, feeding a reputable commercially available balanced diet can help prevent dietary related causes of stone formation. For breeds that are predisposed, this may not be enough to prevent formation. Urine monitoring at your wellness health visits is especially advisable in at-risk breeds.
After surgical removal a prescription diet is prescribed to assist dissolving new stones, correct mineral or pH imbalances, and/or dilute the urine. These diets should be fed exclusively to ensure that maximum benefit is received. Unfortunately there is no guarantee that the stones will not reoccur. It is important that your pet has regular veterinary check-ups to monitor their urine pH and concentration; and look for early crystal formation.