Veterinary care should include diagnostic tests and subsequent treatment recommendations. Diagnosis In-depth
Diagnostic tests must be performed to confirm the diagnosis of CRF and exclude other diseases that may cause similar symptoms. Tests may include: Your veterinarian should perform a complete medical history and a thorough physical examination.
Complete blood count (Hemogram; CBC) may be performed to evaluate for signs of infection, inflammation, anemia or platelet abnormalities. Performing a buccal mucosal bleeding time may best assesses abnormal platelet function.
A biochemistry analysis (biochemical profile tests), such as serum creatinine and BUN concentrations are typically elevated with CRF. Serum phosphorus and potassium concentrations may also be increased.
Urinalysis tests may show a low specific gravity, which is common with CRF. Abnormal urine protein or sediment may indicate infection or glomerular disease.
Abdominal radiographs (X-rays) may show small kidney size, which is common with CRF, but normal renal size does not rule out CRF. Some chronic kidney diseases in cats can be associated with enlarged kidneys (e.g. polycystic renal disease, renal lymphoma).
Other diagnostic tests may be recommended on a case-by-case basis. Tests may include:
Renal ultrasounography can provide additional information about the kidneys. Kidneys with chronic disease are typically small and sometimes irregularly shaped. Large kidneys may indicate polycystic renal disease, cancer or an acute kidney disease. Some pets can have a normal ultrasound with CRF.
Excretory urography may be useful in the evaluation of abnormalities in renal size, shape or location. It may also be valuable in the detection of obstruction, cancer or stones.
Urine culture should be performed to evaluate for the presence of upper or lower urinary tract infection.
Blood gas analysis will allow evaluation of acid base levels.
Leptospira antibody serologic tests may be needed to diagnosis this infection.
Arterial blood pressure may be needed to determine the presence of complicating hypertension (high blood pressure).
A fine need aspirate (biopsy) of the kidney may be useful in some cats with renal diseases (e.g. kidney lymphoma, granulomatous interstitial nephritis due to FIP).
Endogenous or exogenous creatinine clearance can be used to measure glomerular filtration rate in pets with normal blood work who are suspected to have renal disease.
Urine protein/creatinine ratio is useful to evaluate urinary protein loss in pets suspected to have glomerular disease.
Fractional excretion of electrolytes (sodium, potassium, chloride, and phosphorus) may be useful in evaluation of animals with suspected renal tubular disorders.
Radioisotope clearances may be used to determine kidney filtration and blood flow.