Red blood cells morphology and morphometry in adult, senior, and geriatricians dogs by optical and scanning electron microscopy

Abstract

Red blood cells (RBC) morphologic evaluation through microscopy optical (OM) and SEM, provides information to forecast, evaluate, and monitor the functioning of many organs. Factors, such aging and diseases affect RBC morphology in both, human and animals. SEM is useful to evaluate RBC morphology, although its use in diagnosis and evaluation in dogs is limited, due to the availability and cost. The aim of this research was to assess the normal RBC morphology in adult, senior and geriatrician dogs, clinically healthy by OM and SEM. In addition to evaluating the age effect, sex, body size, and their interaction on erythrocyte morphometry. To carry out the research 152 blood samples were evaluated from dogs of different sexes and body sizes (small, medium, and large). Three groups were made based on dogs age: group I adults (1–7.9 years old), group II senior (8–11.9 years old), and group III geriatricians (>12 years old). Erythrocyte parameters were evaluated by OM (diameter, height, and axial ratio). Per each dog, the parameters of 20 erythrocytes were measured. A total of 2,600 cells were scanned with the AmScope™ Software scale. In addition, the RBC morphology was evaluated by SEM. Statistical analyses used analysis of variance and a general linear model, which allows the comparison of multiple factors at two or more levels (p < 0.05). The results of this study showed that diameter and height were lower in adult dogs than in senior and geriatrician dogs (p < 0.05). Whereas, sex, body size, and the interaction did not show a significant effect (p > 0.05). Additionally, some images of anisocytosis, polychromasia, and poikilocytosis (echinocytes, acanthocytes, codocytes, spherocytes, stomatocytes, dacryocytes quatrefoil, and elliptocytes) were obtained by OM and SEM. Our study provides information about the morphological and morphometry alterations of adult, senior, and geriatrician dogs RBC. This work contributes to future investigations and the diagnosing diseases, where it is necessary to evaluate the morphology of RBC.

Comparison of visual assessments of anisocytosis in canine blood smears and analyzer-calculated red blood cell distribution width

“…Variability in erythrocyte size, anisocytosis, is useful for the describing, classifying, or prognosing of pathophysiological phenomena in dogs ( 1 – 4 ), such as anemia ( 5 – 9 ), microcytosis ( 10 , 11 ), quatrefoil red blood cells ( 12 ), cardiopulmonary diseases ( 13 – 18 ), pancreatitis ( 19 ), inflammatory bowel disease ( 20 ), or diabetes mellitus ( 21 ), and of physiological phenomena such as sex and aging ( 22 , 23 ).…”

“…Evaluating a blood smear by conventional microscopy requires experience ( 26 ) and is prone to subjective assessment, which may lead to variability within and between observers. Furthermore, different grading schemes exist, some with very simple categorizations such as “absent or present” ( 9 , 22 ). Others have applied subjective grading on a scale from +1 to +4, with +1 being the smallest amount ( 27 ), or grading +1 to +4 based on the number of variable-sized erythrocytes in a monolayer at 1,000x microscopic field ( 28 ) or high-power field (HPF) ( 21 ).…”