Breed-specific variation of hematologic and biochemical analytes in healthy adult Bernese Mountain dogs

Background Hematology and serum biochemistry reference intervals in dogs may be affected by internal factors, such as breed and age, and external factors, such as the environment, diet, and lifestyle. In humans, it is well established that geographic origin and age may have an impact on reference intervals and, therefore, more specific reference intervals are sought for subpopulations. Objective The objective of this study was to validate and transfer standard laboratory reference intervals for healthy Bernese Mountain dogs and to create new intervals for analytes where the established laboratory reference intervals were rejected. Methods The procedure was performed using the human Clinical and Laboratory Standards Institute-approved model modified for veterinary use. Thirty-two dogs were included in the study using a direct a priori method, as recommended. Results While 23 of the standard laboratory reference intervals were readily validated, 7 of the analytes (eosinophils, MCHC, alkaline phosphatase [ALP], gamma-glutamyltransferase, total bilirubin, amylase, and cholesterol) required new reference intervals according to the standard. These were calculated using the robust method. In particular, the new reference range for ALP was wide compared with the established laboratory reference interval. No clinical causes were found for differences in the results of these analytes. Conclusion We found significant differences in 7 hematologic and serum biochemical analytes for which a breed-specific variation appears to be the most plausible explanation. Breed-specific reference intervals for Bernese Mountain dogs will help avoid misinterpretation of laboratory results in the diagnostic process.