Comparison of point-of-care analysis using Coaguchek XS and standard laboratory-measured prothrombin time in dogs

AIMS: The Coaguchek XS is a hand-held coagulation monitor, which is widely available for human testing, and could have applications for canine samples. The aim of this study was a preliminary evaluation of the suitability of this point-of-care device to determine prothrombin time (PT) in dogs by measuring the clinical agreement between the results obtained using the device and standard laboratory testing. METHODS: The PT in 24 samples from 13 dogs with suspected coagulopathy and 40 samples from 40 healthy dogs was determined concurrently using the point-of-care device and standard laboratory analysis. The clinical agreement between methods was assessed using Bland-Altman analysis and error grid analysis. RESULTS: Four of the paired samples were not suitable for analysis. The point-of-care device showed a 1.29 fold positive systematic bias which, when corrected for, gave excellent clinical agreement. Differences in the results obtained would have influenced clinical decision making in only 3 of 60 (5.0%) samples where the point-of-care result suggested a more prolonged PT than laboratory testing. A measurement error occurred in two point-of-care samples which may have been due to the combination of severe anaemia and severely prolonged PT. CONCLUSIONS AND CLINICAL RELEVANCE: The point-of-care device can be used in dogs and would provide rapid analysis of PT to aid clinical decision making in dogs with suspected rodenticide toxicity. Development of a device-specific reference range for dogs would improve its value.