Age and sex influence in canineRed Cell Distribution Width (RDW-CV and RDW-SD) values

Abstract

ResumoO objetivo do presente estudo foi verificar a influência da idade e do sexo nos valores dos índices RDW-CV (Amplitude de distribuição de hemácias como coeficiente de variação) e RDW-SD (Amplitude de distribuição de hemácias como desvio-padrão) em hemogramas de cães clinicamente sadios. Foram analisados os resultados de 332 hemogramas de cães, sendo 136 machos e 196 fêmeas. Os animais foram divididos em três grupos de acordo com a idade: animais até um ano (n = 42), animais entre um e nove anos (n = 104) e animais acima de 9 anos (n = 186). Todos os exames foram processados no Contador Hematológico Automatizado Veterinário Sysmex® -Poch 100 iV, no período de setembro de 2009 a setembro de 2010 e os resultados foram confirmados por análise microscópica dos esfregaçossanguíneos. Os valores médios e os desvios-padrão para RDW-CV (%) foram de 10,74 ± 1,53, próximos aos valores citados na literatura. Para RDW-SD (fL),os valores obtidos foram de 32,01 ± 7,56. Entretanto, nos trabalhos já realizados, não foram encontrados valores de referência para este índice em cães. Não houve diferença significativa nos valores encontrados para estes índices entre machos e fêmeas ou entre as diferentes faixas etárias, podendo ser utilizados como referência para ambos os sexos e todas as idades.Palavras-chave: anisocitose, cão, hematologia. AbstractThe aim of this study was to verify age and sex influence on RDW-CV (Red blood cell distribution width measured by Variation Coefficient)and RDW-SD (Red blood cell distribution width measured by Standard Deviation) values in healthy dogs' blood tests. Were analyzed the results of blood tests of 332 dogs(136 males and 186 females). These results were further divided into three groups according to age: animals up to one year (n = 42), with one to nine years (n = 104) and over nine years (n = 186).All Complete blood count (CBC) tests were processed in the Automated Veterinary hematology counter Sysmex ® -Poch 100 iV during the period September 2009 to September 2010 and the results were confirmed by microscopic analyses of blood films. The mean values and standard deviations for RDW-CV (%) were 10.74 ± 1.53, similar to values cited in literature. For RDW-SD (fL) the obtained values were 32.01 ± 7.56. However, there are no reference values for this index in literature for dogs. There was no significant difference in values for these indices between males and females or different age groups. These data can be used as reference for both genders within all ages.

Platelet indices in dogs with thrombocytopenia and dogs with normal platelet counts

“…These MPV results may suggest a low sensitivity of this index to platelet heterogeneity similar to what occurs in MCV for red blood cells, which requires a large number of erythrocytes with different volumes for this index to increase (Souza et al 2012). However, in this study, it is possible that there were no differences in thrombocytopenic animals` MPV values due to higher number of dogs with platelet counts between 150,000/µL and 200,000/µL, therefore, requiring greater number of dogs with severe thrombocytopenia to significantly raise MPV values.…”

“…Increase in automated blood cell analyzers' availability has provided indices that were not previously calculated in manually performed CBCs, such as Red Blood Cell Distribution Width (RDW), which has led to new approaches in anemic patients (Balarin et al 2001, Žvorc et al 2010, Temizel et al 2011, Souza et al 2012.…”

“…Regardless of reticulocyte counts and bone marrow cytological examinations, regeneration can be evaluated by using RBC and platelet indices (Flaiban and Balarin 2004). Souza et al (2012) demonstrated RBC indices provide important information on anemia in dogs, therefore, platelet indices can provide clinical information on thrombocytopenia's underlying conditions. Platelet volume indices, such as Mean Platelet Volume (MPV), which represents average platelet size, and Platelet Distribution Width (PDW), which represents platelet size heterogeneity, are now routinely available.…”

Hematological evaluation of free‐living golden‐headed lion tamarins (Leontopithecus chrysomelas) from an Urban Atlantic Forest

“…Females in beginning pregnancy could present decreased erythrocyte volume that could be detected by anisocytosis indices. Also, anisocytosis detected by erythrocytes with increased size could be related to an erythropoiesis acceleration status and reticulocytes release that occur in response to hemorrhage status, for example . However, in youth and infants, animals occurred the opposite, and RDW‐CV values were higher on males.…”

“…Both indices were significantly higher ( P < 0.05) in adult females. This index informs size alterations on erythrocytes and has higher sensibility than MCV values . Females in beginning pregnancy could present decreased erythrocyte volume that could be detected by anisocytosis indices.…”