Treatment of urolithiasis must be individualized based on the severity of the condition and other factors that must be evaluated by your veterinarian. Treatment may include one or more of the following: If urinary tract obstruction is present, emergency treatment is required to reestablish urine flow. Relief of obstruction may be accomplished by passage of a well-lubricated urinary catheter or emergency surgery in difficult cases.
Stones may be eliminated surgically or medically depending upon the mineral composition of the stone. There are advantages and disadvantages to both methods. The proper approach will be determined based on your pet's general health, type of stone present, location and number of stones and other factors that your veterinarian will discuss with you.
Ideally, a stone is obtained for analysis to determine its mineral composition and to decide between medical and surgical therapy. Only some stone types can be treated (dissolved) by medical means. Stones that have been passed in the urine can be submitted for analysis or small stones can be obtained by a technique called urohydropropulsion that is performed under general anesthesia. Small stones can be retrieved from the bladder using a technique called catheter-assisted urolith retrieval, which can be performed under sedation.
Surgery is the most direct and efficient way to remove uroliths, relieve obstruction and obtain uroliths for analysis. Dehydration and electrolyte disturbances should be corrected before anesthesia and surgery.
Techniques to dissolve calculi have been developed for some types of stones, such as those composed of struvite (the most common stone type), urate and cystine. An effective dissolution protocol has not been developed for oxalate uroliths, the second most common stone type. Medical dissolution consists of a combination of adjusting urine pH, eradicating bacterial infection, diluting urine and trying to reduce the urinary excretion of minerals found in the calculi. This approach often consists of a special diet and antibiotics to treat bacterial infection.
Dissolution of stones can take several months. Medical dissolution carries with it the risk of urinary obstruction because bladder stones may become small enough to lodge in the urethra as they dissolve and kidney stones can become small enough to lodge in the ureters as they dissolve. Your veterinarian may recommend adding salt to your pet's diet to increase urine production and decrease the concentration of the urine. This approach typically is used for pets with struvite and urate stones but not for those with oxalate or cystine stones. Medical dissolution of stones is not recommenced for patients with heart disease, hypertension, kidney failure or those at risk for obstruction.
A 2 to 3 week course of antibiotics is typically used to treat bacterial urinary tract infection in pets with urolithiasis. Ideally, antibiotic choice is based on bacterial culture and susceptibility testing.
Pets with specific types of stones may receive additional medical treatments:
Allopurinol in pets with ammonium urate calculi
Potassium citrate and the thiazide diuretic hydrochlorothiazide in pets with calcium oxalate calculi
D-penicillamine or 2-mercaptopropionyl glycine in dogs with cystine calculi