Hematologic reference intervals for the Italian Heavy Draft horse

Established breed-specific reference intervals (RIs) are important for monitoring the health status of horses. Breed-specific RIs have been evaluated in horses and other animal breeds, but there are no studies on breed-specific RIs for Italian Heavy Draft horse (IHDH). The aim of this study was to determine hematologic RIs for the IHDH living in central Italy. The comparison between different physiological status (pregnancy) and age (foals and adults) have been executed. Inclusion criteria were established for selection of subjects and for blood collection and handling. Blood samples were collected from 309 apparently healthy horses (mares, stallions and foals). Complete blood count (CBC) was performed on Sysmex-XT1800iV hematology at the Teaching Veterinary Hospital of the University of Perugia. RIs for IHDH were determined by using well-described, modern analytical and statistical methods as recommended by the CLSI and QALS guidelines. Hematologic RIs for the IHDH are reported. Differences between hot-blooded, cold-blooded, and warm-blooded horses are evident. Significant differences have been found for five analytes (WBC, MCHC, PLT, monocytes, basophils) between pregnant and non-pregnant mares and 12 analytes (RBC, Hgb, MCV, MCH, MCHC, RDW, PLT, WBC, lymphocytes, monocytes, eosinophils, basophils) between foals and adults. This is the first study reporting the hematologic RIs in the IHDH. The results suggest that breed-specific RIs should be used for IHDH due to the difference with published data regarding cold-blooded, hot-blooded, and warm-blooded breeds. Moreover, significant variations of hematological analytes have been found between subjects with different physiological status and age.