Method Comparison and Reference Intervals of β-Hydroxybutyric Acid Measurements by Using a Veterinary Point-of-Care Ketone Meter and a Reference Laboratory Analyzer in Central Bearded Dragons (Pogona vitticeps)

Abstract Hepatic lipid accumulation is highly prevalent in managed central bearded dragons ( Pogona vitticeps ), and standard blood biomarkers have proven ineffective for its diagnostic management. Recently, the ketone β-hydroxybutyrate (BHBA) has demonstrated potential in association with the severity of hepatic lipid accumulation in this species. Because BHBA measurement is not readily available to veterinary practices, the purpose of this study was to perform a method comparison assessment between a veterinary handheld point-of-care (POC) ketone meter (NovaVet Ketone/Glucose Meter, Nova Biomedical, Waltham, MA, USA) and a reference laboratory wet-chemistry analyzer (Ortho-Vitros 5600 Analyzer, QuidelOrtho, San Diego, CA, USA). Forty-four adult bearded dragons of both sexes were sampled, and BHBA concentrations were obtained using both analyzers. The veterinary POC ketone meter was found to underestimate BHBA values, with a significant proportional bias. The total observed error was higher than the combined inherent imprecision of the analyzers, but lower than the total allowable error for clinical agreement. A simple corrective formula (× 0.9) was found to improve agreement with the reference analyzer. No interference was observed with packed cell volume, lipemia, hemolysis, and blood glucose. Reference intervals for BHBA on the two analyzers were also provided on 30 healthy bearded dragons free of moderate-to-severe hepatic lipid accumulation. In conclusion, the veterinary POC ketone meter was found to not be analytically equivalent to the reference analyzer, but to have acceptable agreement for clinical use. This supports the use of this POC ketone meter for measuring BHBA in the diagnostic management of hepatic lipid accumulation and assessment of fasting status and peripheral lipolysis in central bearded dragons.