Oliguria and anuria are both indicative of dehydration and/or severe kidney problems. Differentiating between insufficient urine production and urinary obstruction is necessary in order to successfully treat the condition.

Healthy cats typically produce approximately one to two grams of urine for every kilogram of their body weight per hour. Oliguria and anuria are the medical terms that are used to describe insufficient urine production in cats. Oliguria refers to a small amount of urine production. Cats with oliguria typically produce less than 0.25 milliliters of urine per kilogram per hour. Anuria refers to a medical condition where essentially no urine is being produced by the body. Cats with anuria produce urine at a rate of less than 0.08 milliliters of urine per kilogram per hour.

Symptoms may vary depending on the primary cause of oliguria or anuria. These symptoms include:

A variety of conditions can cause oliguria and anuria to occur. These conditions include:

The veterinarian will ask for the cat's complete health history, when urine production decreased or stopped, and what other symptoms are present. A complete blood count, an electrolyte panel, and a biochemical profile will be done. These labs will show any kidney or liver problems in the cat and if dehydration is present. The veterinarian will also physically examine the cat, looking for evidence of a swollen abdomen and an empty bladder.

A urethrocystoscopy will be performed in order to look at the interior of the bladder wall and urinary tract. The veterinarian will look for evidence of urinary obstruction or rupture during this test. An abdominal ultrasound may also be performed to look for problems in the bladder, liver and/or kidneys. If kidney disease or failure has occurred, the veterinarian may opt to do a kidney biopsy. During the biopsy, a small sample of the kidney tissue will be removed and examined by the laboratory to determine the primary cause of the kidney problems.

Both oliguria and anuria must be treated immediately in order to prevent death from occurring. The primary cause of the oliguria or anuria must be addressed in order to increase urine production. The following may be recommended by the veterinarian to treat the cat:

If the cat is extremely dehydrated, intravenous fluid therapy will be administered. The cat's weight will be taken prior to the fluid therapy beginning and a catheter will be inserted. Urinary output, total weight, and blood work will be continually monitored to ensure that the cat's organs are responding appropriately to the fluid.

There are a variety of medications that the veterinarian may prescribe to stimulate urine production. Mannitol works by increasing blood flow to the kidneys, which may help the kidneys to function better. This drug is administered intravenously and typically works within 15 to 30 minutes. Furosemide is a medication that may also be prescribed that alters the electrolyte balance in the blood, which can stimulate urine production. If other medications aren't successful, the veterinarian may prescribe dopamine. Dopamine works by dilating the blood vessels.

If fluids and medications aren't successful, hemodialysis may be considered. Hemodialysis works as an artificial kidney, filtering the blood through a machine that removes excess fluid, toxins, and waste from the cat's body. Unfortunately, veterinary dialysis is only available in a few cities in the United States. If a veterinary dialysis center is nearby, dialysis must begin as soon as it has been determined that medications were not successful at producing urine.

If not promptly treated, cats who have oliguria or anuria may die within a few hours or days. Even with treatment, the prognosis is guarded in cats who with anuria. Successful treatment depends on the cat producing urine within six hours of diagnosis. 

The cat will need to remain hospitalized until urine output is normal. Primary conditions that caused decreased urine production will need to be followed up with the veterinarian on a regular basis in order to monitor the condition.