High Level of Agreement Between Blood Glucose Concentrations Measured With the AlphaTrak 3 Point-of-Care Glucometer and by Colorimetry in a Psittacine (Rosy-faced Lovebird,), but Not in a Passerine (House Finch,).

Abstract

Commercial point-of-care (POC) devices are commonly used to rapidly and cost-effectively measure the concentrations of vertebrate blood components such as metabolites and electrolytes. However, these devices can provide inaccurate results, and their utility must be rigorously tested by comparing results with those obtained from a reference assay. This study evaluated the accuracy of the veterinary AlphaTrak 3 glucometer (Zoetis, Kalamazoo, MI, USA) for use in 2 phylogenetically distant avian taxa, the house finch (, order Passeriformes) and the rosy-faced lovebird (, order Psittaciformes), compared with an enzyme end-point colorimetric assay (Cayman Chemical, Ann Arbor, MI, USA) as the reference. This POC device was used to measure blood glucose in 30 house finch and 32 rosy-faced lovebird samples. The level of agreement between assays and the POC device reliability were determined with the Bland-Altman method and the Pearson product moment correlation. All the samples contained detectable glucose concentrations, but 9 finch samples had glucose concentrations exceeding the glucometer's upper detection limit and were eliminated. The POC device produced consistent results for both species. Relative to the reference assay, the glucometer overestimated glucose concentrations by 3.8% in house finch samples and by 8.7% in rosy-faced lovebird samples. There was good agreement between glucose concentrations measured with the 2 assay methods in the rosy-faced lovebird, but not in the house finch (allowable error <15%). These findings confirm the need to test the validity and accuracy of measurements with commercial glucometers, and they highlight that the reliability of these devices should be tested for each species under consideration.