A single-blood-sample method using inulin for estimating feline glomerular filtration rate.

Abstract

BACKGROUND: Application of a multisample method using inulin to estimate glomerular filtration rate (GFR) in cats is cumbersome. OBJECTIVES: To establish a simplified procedure to estimate GFR in cats, a single-blood-sample method using inulin was compared with a conventional 3-sample method. ANIMALS: Nine cats including 6 clinically healthy cats and 3 cats with spontaneous chronic kidney disease. METHODS: Retrospective study. Inulin was administered as an intravenous bolus at 50 mg/kg to cats, and blood was collected at 60, 90, and 120 minutes later for the 3-sample method. Serum inulin concentrations were colorimetrically determined by an autoanalyzer method. The GFR in the single-blood-sample method was calculated from the dose injected, serum concentration, sampling time, and estimated volume of distribution on the basis of the data of the 3-sample method. RESULTS: An excellent correlation was observed (r = 0.99, P = .0001) between GFR values estimated by the single-blood-sample and 3-sample methods. CONCLUSIONS AND CLINICAL IMPORTANCE: The single-blood-sample method using inulin provides a practicable and ethical alternative for estimating glomerular filtration rate in cats.