Why Is My Dog Or Cat Azotemic?

Why Is My Dog Or Cat Azotemic?

Ron Hines DVM PhD

See What Normal Blood & Urine Values Are

The Causes Of Most Abnormal Blood  & Urine Tests

See How Tests Are Grouped

Azotemia – It was once called uremic poisoning, uremia or just kidney failure.

Veterinarians say that your cat or your dog is “azotemic” when the amount of urea and creatinine in its blood is above normal. Urea and creatinine are waste byproducts of the protein metabolism that naturally occurs in all mammals. When their level in your pet’s blood rises above normal, it is a sign that the dog or cat’s kidney have been damaged. A more common name for that same situation is uremia.

Conditions That Can Causes Azotemia In Your Dog And Cat:

The most common condition that decreases the capacity of your dog or cat’s kidneys to move urea and creatinine out of your its blood stream and into its urine for elimination is a reduced glomerular filtration rate= GFR). That is the rate that blood racing through the tangle of tiny blood vessels in the individual filtering units in your pets kidneys are able to produce concentrated urine. That reduction can be due to kidney damage (renal causes) or a decrease in the amount of blood passing through your pet’s kidneys (pre-renal causes) like the inefficient blood circulation that occurs in heart disease, inadequate fluid intake or even the dehydration produced by vomiting or diarrhea. It can also be caused by any obstruction that prevents or limits  urination. In cats and dogs that could be a struvite  or oxalate crystal blockade. 

When BUN and Creatinine rise significantly in your dog or in  your cat’s blood due to kidney disease (renal causes), veterinarians believe that about two-thirds of the pet’s kidney’s filtering units, the glomeruli, are not functioning.

Situations When Your Dog Or Cat’s Urea and creatinine levels might be lower than normal – the opposite of azotemia:

The most common causes are starvation and malnutrition. When pets do not consume sufficient protein, their BUN and creatinine levels often drop below normal.  All food proteins contain nitrogen as a major ingredient. Nitrogen (-N) is also the major component of urea.  and  creatinine.   Severe liver disease can cause similar effects. That is because many of the food protein conversion processes normally occur in the liver. (read here)

Complementary Tests:

Urine specific gravityComplete urinalysis, Tests to check for secondary correctable problems associated with kidney failure such as:  anion gap, blood phosphorus level, blood potassium and magnesium level,  PCVreticulocyte count, You pet’s response to IV fluids. Urine specific gravity is less diagnostic of kidney disease in cats than in dogs. After-trauma: imaging techniques to confirm your dog or cat’s kidney and bladder integrity.


You are on the Vetspace animal health website

Visiting the products that you see displayed on this website help pay the cost of keeping these articles on the Internet.