Kidney Failure and Excess Urea in the Urine in Cats


PetMD Editorial

Published Feb. 5, 2009

Renal Failure and Acute Uremia in Cats

The sudden onset of abnormally high levels of urea, protein products, and amino acids in the cat's blood is referred to as acute uremia. This condition usually follows kidney injuries or occurs when the urinary tubes that connect the kidney to the bladder (ureters) are obstructed. As a result, the outflow of urine is obstructed, creating an imbalance in fluid regulation and leading to a buildup of potential toxins in the body. Fortunately, acute uremia can be successfully treated and cured if it is identified on time and treated promptly.

Most cat breeds, whether male or female, are affected by acute uremia; however, exposure to chemicals such as antifreeze increases the risk of uremia. Therefore, the incidence of acute uremia is higher in the winter and fall than in other seasons.

The condition described in this medical article can affect both dogs and cats. If you would like to learn how acute uremia affects dogs, please visit this page in the PetMD health library.

Symptoms and Types

As this potentially toxic blood flows through the cat's body, most systems are affected, including the urinary, digestive, nervous, respiratory, musculoskeletal, lymphatic, and immune systems.

Upon examination, cats will appear to be in normal physical condition, but may appear to be in a depressed state. When symptoms are apparent, signs can include loss of appetite, listlessness, vomiting, and diarrhea, which may be tinted with blood. Other symptoms may include inflammation of the tongue, ammonia-smelling breath (due to the urea), ulcers in the mouth, fever, abnormally fast or slow pulse, decreased or increased urine output, and even seizures. The kidneys may feel enlarged, tender, and firm on palpation.


Kidney failure or obstruction to urine output may be due to any of the following:

  • Kidney inflammation
  • Kidney or ureteral stones
  • Presence of foreign bodies in the ureter(s)
  • Damaged kidney tissue that causes back-flow of urine
  • Low blood flow to the kidneys as a result of trauma, excess bleeding, heat stroke, heart failure, etc.
  • Ingestion of chemicals (e.g., some pain killers, dyes used for internal imaging, mercury, lead, antifreeze)


A complete blood profile will be conducted by your veterinarian, including a chemical blood profile, a complete blood count, and a urinalysis. Cats with acute uremia may have high packed cell volume and an increased white blood cell count. The levels of certain protein enzymes and chemicals such as creatinine, phosphate, glucose, and potassium will also be high.

Urine may be collected by inserting a catheter or a fine needle aspiration into the cat; the results of which may show high levels of protein, glucose, and the presence of blood cells. In order to view and examine the urinary system clearly, contrast dyes may be injected into the bladder so that the interior of the bladder, the ureters, and the kidney are illuminated on the X-ray and ultrasonography imaging.


If the uremia is due to toxic poisoning, the first step will be to eliminate the toxins from the body. This may be done through gastric lavage, where the stomach is cleansed, or by administering activated charcoal to neutralize the toxin. Specific antidotes may also be administered if the toxic agent can be identified.

Care is also aimed at re-establishing fluid balance, blood circulation, and in establishing the balance of chemicals in the blood. Strictly monitoring fluid intake, food consumption, and nutrition is very important while treatment is underway.

Some medications that may be prescribed are:

  • Diuretics
  • Antiemetics
  • Dopamine derivatives
  • Mucosal protectants to counteract acidity
  • Bicarbonates to re-establish chemical balance in the body

Based on your cat's response to these drugs, your veterinarian might also recommend dialysis or surgery.

Living and Management

Generally, this condition has a poor prognosis for recovery. Some potential complications include seizures, coma, high blood pressure, pneumonia, bleeding in the digestive tract, cardiac arrest, fluid overload, widespread infection in the blood, and multiple organ failure.

The cost involved of treating an animal with acute uremia may also very high. Sometimes, dialysis can be used until the cat is stable enough to tolerate surgery.

After the procedures are complete, it is important to monitor daily fluid levels, mineral levels, body weight, urine output, and general physical status. The entire process of recovery depends on various factors, such as the extent of organ or system damage, the origin of the disease, and the existence of other pathological conditions or diseased organs.

Image: VGstockstudio via Shutterstock

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