Urolithiasis, Urate

Urolithiasis is a medical term referring to the presence of stones or crystals in the animal'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 animal's bladder (ureters).

While these stones can affect any cat or dog breed, Dalmatians, English Bulldogs, and Yorkshire Terriers are more susceptible to the condition. It is also more common in male animals than in females, and 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 the animal is positive.

Symptoms and Types  

While many animals 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, cloudy urine, and eventually the complete inability to urinate (anuria).

Causes

Animals 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.

Diagnosis

Ultrasounds are often performed to determine the size, shape, and location of the stones, helping the veterinarian come up with an appropriate treatment regimen. Bloodwork will also be performed to determine if there are any underlying medical conditions causing the stones.

Treatment

If the animal is unable to urinate because of blockage, surgery is often required. In the event the animal 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 disolve the stones and this method takes about four weeks to complete.

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 of surgery.

Prevention

A low purine diet has shown some promise in the prevention of the formation of these stones.