High Levels of Blood Nitrogen in Dogs

Azotemia is a medical condition that describes higher than normal levels of nitrogen-based compounds in the blood such as urea, creatinine and other compounds. It can be due to kidney failure (a decrease in the glomerular filtration rate (GFR) of the kidneys), higher than normal production of nitrogen containing substances  or reabsorption of urine back into blood stream. 

Uremia also describes accumulation of nitrogenous waste products in the blood  but it is specifically concerned with kidney failure. In uremia, nitrogenous waste products are found in higher than normal values in the blood but the cause is renal (kidney) failure. 

Azotemia can be differentiated into three categories based on the causative origin. However, all forms are characterized by a decrease in the glomerular filtration rate (GFR) of the kidneys and increases in blood urea nitrogen (BUN) and serum creatinine concentrations. The three forms of azotemia are Prerenal azotemia (occurs when blood flow to kidneys slows down secondary to shock, hemorrhage, congestive heart failure or renal artery stenosis), primary renal azotemia (occurs secondary to renal failure) and postrenal azotemia (occurs due to blockage in urine flowbelow kidney area).

Azotemia may or may not be associated with historical or physical abnormalities. Unless animal has uremia, clinical findings are limited to the disease responsible for azotemia (eg, hypoadrenocorticism and urinary obstruction). Findings described here are those of uremia.

Weight loss 

Declining appetite or anorexia 

Reduced activity 






Halitosis (bad breath)


Poor haircoat or unkempt appearance

Muscle Wasting 





Petechia and ecchymosis 

Dull and unkempt haircoat 

Uriniferous breath 

Uremic stomatitis 

Scleral and conjunctival injection

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