Preliminary study of hematological changes observed in coagulated blood samples from dogs and cats

Abstract

Introduction. Clot formation in blood samples is a common pre-analytical error in veterinary medicine and can be easily prevented through proper collection practices. Objective. This study compared complete blood count (CBC) results obtained from canine and feline blood samples divided into two groups, clotted and non-clotted, in order to determine whether clot formation causes significant alterations in the hematological evaluation of these species. Materials and Methods. EDTA-anticoagulated blood samples from twelve patients (six dogs and six cats, including three males and three females of each species) were analyzed. Each patient provided one adequate sample and one clotted sample. Hematological analyses were performed using an automated hematology analyzer and blood smear evaluation. Results were assessed according to reference intervals for clinical interpretation and were also statistically analyzed to determine significant differences between groups. Results and Discussion. All CBCs performed using clotted samples showed significant variations compared with the results obtained from non-clotted samples. Statistically significant differences were observed in total leukocyte count, monocyte count, and platelet count. The greater discrepancies observed in cats may be related to their predisposition to platelet aggregation and microclot formation, as well as to the morphological characteristics of feline blood cells. These factors may increase the impact of clot formation on hematological results. Conclusion. Clotted blood samples do not provide reliable CBC results and, in many cases, the findings do not accurately reflect the patient's true hematological status. Such discrepancies may lead to misdiagnosis and negatively affect clinical decision-making and therapeutic management by the attending veterinarian.