Feline azotemia

• Azotemia is an increased concentration of nonprotein nitrogenous compounds (eg urea and creatinine) in the blood. "Uremia" is the clinical syndrome that occurs as a result of severe azotemia due to abnormal renal function. • Causes: ◦ Reduced glomerular filtration rate: - Reduced renal perfusion (pre-renal azotemia). - Primary renal disease (renal azotemia). - Obstruction to urinary outflow (post-renal azotemia). ◦ Uroabdomen leading to reabsorption of urinary nitrogenous compounds (post-renal azotemia). ◦ Increased absorption of nonprotein nitrogenous compounds from the gastro-intestinal tract, eg GI bleeding, high protein meal. ◦ Increased protein catabolism, eg fever, trauma, burns, hyperthyroidism. • A degree of pre-renal azotemia may be super-imposed on pre-existing renal or post-renal azotemia