Abstract

Uric acid is a primary clinicopathologic marker of renal function in birds and reptiles. Point-of-care uric acid meters are available for human gout management, providing rapid results using only a drop of blood.^1,2 Utility of these meters in animals have yet to be investigated. Small patient size of some birds and reptiles can limit blood volume safely and easily collected; thus, this technology would allow rapid assessment of non-mammalian uric acid concentration with minimal blood volume. Whole blood uric acid concentrations were measured immediately after jugular venipuncture in 21 fasted, healthy, adult Magellanic penguins (Spheniscus magellanicus) using the UASure® Blood Uric Acid Meter (UASure®, Atwood, CA, USA). Plasma uric acid concentrations were measured that day at IDEXX via bench-top chemistry analyzer (Beckman AU5800, Beckman Coulter, Inc., Brea, CA, USA). Mean±SD uric acid concentrations for the UASure® and IDEXX results were 6.1±1.3 and 6.9±2.0 mg/dl, respectively. Passing-Bablok regression analysis revealed systematic (intercept = -3.2, 95% CI: -6.5 to -0.56) and proportional differences (slope = 1.7, 95% CI: 1.2–2.2) between methods. A Bland-Altman plot revealed a mean negative bias of -0.81±1.1 mg/dl between the methods. As uric acid concentration increased, the difference between UASure® and IDEXX results increased and became more negative. All values fell within reference intervals for this species, and the differences were deemed not clinically significant on an individual basis.³ While the two methods were not in statistical agreement for Magellanic penguins, the UASure® Blood Uric Acid Meter has potential for rapidly estimating uric acid concentration, especially in emergency cases.

Acknowledgments

The authors thank the animal care staff of the Shedd Aquarium for support and assistance during sample collection, and the technical staff of the Shedd Aquarium Animal Health department (Rachel Parchem, Lauren Czudak, Bernadette Maciol, and Sage Rosenbrock) for assistance with sample collection and processing.

Literature Cited

1.  Kuo CS, Hwu CM, Lin YH, Huang YH, Kao WY, Weih MJ, Hsiao LC, Kwok CF, Ho LT. Portable electrochemical blood uric acid meter. J Clin Lab Anal. 2002;16(2):109–114.

2.  Paraskos J, Berke Z, Cook J, Miner JN, Braddock M, Platt A, Hughes G. An analytical comparison between point-of-care uric acid testing meters. Expert Rev Mol Diagn. 2016;16(3):373–382.

3.  ZIMS Expected Test Results for Spheniscus magellanicus. 2019. Species360 Zoological Information Management System. Available from https://zims.species360.org.