Urolithiasis/Urate Stones in Cats
Urolithiasis is a medical term referring to the presence of stones or crystals in a cat's urinary tract. When the stones are made up of uric acid, they are called urate stones. These stones can also be found in the kidneys and in the tubes connecting the kidneys to the bladder (ureters).
While these stones can affect any cat breed, the condition does tend to be more common in male animals than in females. It is typically noticed within the first three to four years of life.
It is highly likely the stones will recur after treatment, but the overall prognosis for a treated cat is positive.
Symptoms and Types
While many cats will not show any signs of the disease, the most common symptoms usually deal with urination issues. These can include abnormal urine streams, difficulty urinating (dysuria), blood in the urine (hematuria), cloudy urine, and eventually the complete inability to urinate (anuria).
Cats that have an abnormal connection of the main blood vessel in the liver, called a portosystemic shunt, have a higher incidence of developing these types of stones in the urinary tract. A diet consisting of high amounts of purine – found in beef, poultry and fish – can also cause this condition.
Ultrasounds are often performed to determine the size, shape, and location of the stones. This information will help your veterinarian to determine an appropriate treatment regimen. Bloodwork will also be performed to determine if there are any underlying medical conditions causing the stones.
If your cat is unable to urinate because of blockage, surgery is often the required treatment. In the event the cat has an abnormal connection of the main blood vessel in its liver – as mentioned above – surgery can be performed to re-route blood flow.
Medications are sometimes prescribed to dissolve the stones; this method takes about four weeks to completely resolve the matter.
Living and Management
To monitor for a the recurrence of stones, ultrasounds and X-rays should be performed every two to six months. If caught early, the stones are easy to treat without the need for surgery.
A low purine diet has shown some promise in the prevention of the formation of these stones.