Urea Nitrogen Level in Cats

Urea is a chemical made from ammonia in the liver. Ammonia is absorbed in the digestive tract from the breakdown of proteins found in food. After the liver produces urea, it is excreted from the body by the kidneys.

  1. Definition

    • Blood urea nitrogen (BUN) is an indirect measurement of kidney function in the cat. In a cat with normal kidney function, BUN levels are low. In a cat with kidney disease, BUN levels are high.

    BUN Elevations

    • BUN levels can also be elevated when a cat is dehydrated. Cats that develop a blockage in the urinary tract can also have high BUN levels. Very high protein diets can also cause high BUN levels.

    Aging Effects

    • As a cat ages, it is more likely to develop kidney failure. Periodic measurements of BUN levels will help monitor an older cat's kidney function.

    BUN and Kidney Failure

    • BUN and other toxins normally excreted by the kidneys build up in a cat with renal failure. This causes the cat to vomit, drink more than normal and produce more urine.

    Treatment

    • Treatment for a cat with high BUN levels and renal failure include special diets and fluid therapy. Fluids can be given in the vein or at home under the cat's skin.