Hematological reference values of horses in Western Libya and their relationship to breed, age, and management

Hematological evaluation is an important step for health assessment in equine medicine. Besides biochemical tests, that evaluation could be pivotal for diagnosis, prognosis, and treatment monitoring. In Libya, the horse population has drastically increased in the last years, and hitherto, no report addressed the reference hematological values for the existing equine breeds.

This study aimed to establish the reference for hematological indices of traditional equestrian and stud-farm equine breeds in Western Libya in regard to some variables such as individual characteristics, management system, and rearing purpose.

Blood samples of 167 horses of Arabian, Thoroughbred, and local breeds were collected from an area covering a large part of Western Libya and complete blood counts of the samples were performed using a hematological auto-analyzer. The collected data were statistically analyzed using the Statistical Package for Social Science software.

Hematological reference indices were generated for the aforementioned equine breeds in Western Libya. The equine hematological profile was variable according to some individual and management factors. In addition, the significant effects of those factors were usually restricted to erythrocyte- and platelets (PLTs)-related indices. In terms of breed influence, Thoroughbreds had significantly lower erythrocyte counts of red blood cells (RBCs) compared to local horses (p = 0.04), and Arabian horses showed significantly higher PLT counts compared to Thoroughbreds and local horses; p = 0.00 and p = 0.03, respectively. Moreover, significantly lower values of hemoglobin (HGB), hematocrit (HCT), mean cell volume (MCV), and PLT counts were noticed in young horses vis-à-vis significantly higher values of HCT, mean corpuscular hemoglobin concentration and red cell distribution width in females. In regard to exercise, racing horses varied significantly from nonracing horses in monocyte percentage (p = 0.04), RBC (p = 0.00), HGB (p = 0.00), HCT (p = 0.00), MCV (p = 0.00), and mean corpuscular hemoglobin (MCH) (p = 0.00). Diet supplementation also influenced the equine erythrocyte-related indices, as horses offered supplemented diet had significantly higher RBC (p = 0.00), HGB (p = 0.00), HCT (p = 0.00), MCV (p = 0.00), and MCH (p = 0.00), comparing to those served nonsupplemented diet.

This study provided the first reference values of the equine hematological profile in Western Libya. In addition, the age, breed, exercise, and diet supplementation had variable impacts on hematological equine indices.