Italian researchers believe that a wide number of “healthy” variables—such as breed and geographic location—might impact horses’ blood test results. And with the current textbook reference hematology values being based on the Thoroughbred horse in the United Kingdom, the team believes it might be time to develop new reference values for different breeds in different parts of the world.

“The risk is not having a correct diagnosis and having it really wrong, because it is really impossible that horses living in different environments would have the same blood parameters,” said Barbara Padalino, PhD, researcher at the University of Bari Aldo Moro Veterinary School, in Bari.

Although some research has focused on different hematology parameters for different breeds, no studies have evaluated the different values for different regions, she said. Some previous study results suggest climate could impact hematology parameters, but current reference values do not take climate or geographical location into account.

Hematology values are very important in assessing general health, fitness, stress, and welfare in performance—especially racehorses, Padalino said. They can also be indicators of overtraining, allowing stable managers to make informed decisions about changes in training programs for individual horses