Urinary Tract / Kidney Stones (Cystine) in Dogs

As in people, kidney and bladder stones can develop in dogs. Mineral formations, called uroliths, are like tiny rocks or crystals that can develop in the bladder. Kidney stones, or cystine stones, are formed by cystine, which is an amino acid in the body. Dogs are more susceptible to bladder stones than kidney stones, and in rare occurrences can develop bladder stones that are made up of cystine stones.

Urinary tract  kidney stones, called urolithiasis in veterinary terms, are stones made up of minerals, which usually form in the kidneys and develop in the bladder. These stones, if left untreated, can cause blockage of the bladder and can be fatal. The symptoms are noticeable and can alert the pet owner to this condition, thus getting the dog effective and successful treatment.

There are many different symptoms that are caused by urinary stones or kidney stones. These symptoms can coincide with one another. Both types of stones can have very similar symptoms and include:

• Increased urgency in urinating
• Urinating in unusual places
• Straining when urinating
• Painful urination
• Irregular urine flow, often a little at a time
• Blood or pus in the urine
• Cloudy or odd-smelling urine
• Frequent licking of genitals
• Uncomfortable pacing or panting
• Fever
• Malaise or restlessness
• Crying or whimpering
• Vomiting

 Types

Bladder stones in dogs can form anywhere in the urinary tract. They can be found in the kidneys, ureters, urethra, and the bladder. In the majority of cases, the stones are found within the bladder. Here are different types of stones:

• Struvite bladder stones are comprised of magnesium ammonium phosphate.
• Chemical compounds, such as cystine, calcium phosphate, calcium oxalate, and ammonium urate make up other bladder and kidney stones.
• Often, stones found in the bladder and kidneys are composed of a mixture of the chemical compounds above.
• Different breeds are susceptible to different types of stones, made up of different chemical compounds.

Much research has been conducted on what causes kidney and bladder stones in canines. Causes of these stones can be from the following:

• Genetics
• Amount of minerals in the diet
• Volume of water the dog drinks daily
• Quantity of protein in the diet
• The dog’s urine acidity or alkalinity (affected by diet)
• Infections caused by bacteria in the bladder

If you see any symptoms, such as the dog having difficulty urinating, irregular urine flow, blood in the urine, a foul odor, or any of the other symptoms listed above, then make an immediate phone call to the veterinarian. The veterinarian will instruct you on what you need to do before the dog comes in to visit, such as collecting a free-catch urine sample. More than likely, the veterinarian will want you to bring him in immediately in case he has a blocked urethra, which is an emergency.

During the examination, your veterinarian will feel around the bladder area of the dog (if he is not in too much pain) and identify any stones. Cystine stones in the bladder can be too small to detect by that method, so the veterinarian will make the decision on what to do next. The cystine stones are far too tiny to be seen by radiographing, so he will probably choose to do an ultrasound or other imaging technique.

Treatment options for urolithiasis in dogs include non-surgical, surgical, and ultrasonic dissolution.

Non-Surgical

• Urohydropropulsion is a non-surgical method of flushing out the bladder stones using a special catheter. This method is successfully accomplished only when the stones are very small. Oftentimes, with very tiny stones, the veterinarian will use a cystoscope to remove the stones by inserting it through the urethra and into the bladder. Both of these methods can also be used to collect a stone to sample in a laboratory, and to further determine treatment options, such as changing the dog’s diet to help the stones dissolve (dietary dissolution).

Surgical

• If the stones are large and cannot be removed non-surgically, then surgical removal may be performed. This option may be decided upon if there are too many stones, or if there is any obstruction or risk of obstruction. This quick method of getting rid of the stones does have risks, such as in canines who have other health impairments or may react negatively to anesthesia. In surgery, the bladder is opened up and the stones are removed. There are times when surgery is the only option in order to save the life of the dog, such as if the dog has a blocked urethra, as this can be fatal.

Ultrasonic Dissolution

• Ultrasonic dissolution is an effective method ofn treating bladder and kidney stones. This technique uses ultrasonic waves at a high frequency to break the stones apart. Once the stones are broken into very small pieces, they can come out of the bladder much easier and much less painfully. This may be an ideal option for many dogs, as it is non-surgical and has immediate results.

There are different types of bladder and kidney stones, with cystine bladder stones being quite rare. Dogs that have been treated for cystine bladder stones, even successfully, will have to be on a therapeutic diet for the rest of their lifetime. Prescription dog foods for this purpose have the proper ingredients that allow for an alkaline urine output. Many of these prescription dog foods are very wet to help with the proper quantity of water in the dogs’ diet. It will be vital to make sure your dog follows a strict diet of the proper dog food so the stones do not return.

While the prognosis is good for dogs with this condition, if your dog is recovering he will have to be monitored for symptoms for the rest of his life. Becoming educated on the symptoms of the bladder and kidney stones will keep you proactive in your dog’s condition.