Variability of hematological parameters and establishment of reference intervals in preclinical studies. Part 2: order carnivora

Assessment of the qualitative and quantitative composition of blood is an important aspect of monitoring the health of laboratory animals and evaluating the correctness of experiments. For this purpose, a general or hematological analysis is used, which allows you to obtain the necessary data without significant time costs. Hematological analysis includes the determination of the number, percentage, and morphological characteristics of shaped blood elements such as erythrocytes, leukocytes, and platelets. Indices of these elements, pathological cell forms and inclusions are also taken into account. To improve the accuracy of the results obtained in preclinical studies, it is recommended to use our own reference intervals of hematological parameters of healthy animals, taking into account local preanalytical, analytical and postanalytical features of the work. This work is the second part of a series of studies aimed at establishing reference intervals of hematological parameters of healthy laboratory animals, including ferrets, cats and dogs, united under the common name predators (order carnivora). The age of all animals corresponded to puberty, and males and non-pregnant unborn females were included in the study, without taking into account the phase of the menstrual cycle. The study was conducted using data obtained from intact animals in the period from January to August 2024 at research and manufacturing company “Home оf Pharmacy”. The study was divided into two stages: assessment of indicators using a hematological analyzer and calculation of the leukocyte formula using microscopic analysis. During the hematological analysis of whole blood of animals, the following parameters were determined: the total number of erythrocytes, hematocrit, hemoglobin concentration, average volume of erythrocytes, average hemoglobin content in erythrocytes, average hemoglobin concentration in erythrocytes, total platelets, total leukocytes, as well as the number of lymphocytes and granulocytes. When calculating the leukocyte formula, the following indicators were determined: the content of rod-shaped and segmented neutrophils, eosinophils, monocytes, basophils and lymphocytes. The obtained intervals were compared with data from literary sources and values typical for humans. The discrepancies between the calculated values and the literature data are due to differences in the parameters of erythrocyte indices, as well as in the number of platelets, leukocytes, neutrophils, lymphocytes, eosinophils and reticulocytes. During the study, reference ranges were identified that can become a valuable tool for tracking the health status of laboratory animals during preclinical studies. These data will contribute to improving the quality and accuracy of the experiments conducted, as well as improving the safety and welfare of animals.