White blood cell differentials in dogs with congestive heart failure (CHF) in comparison to those in dogs without cardiac disease

Abstract

Objectives: To determine if dogs with congestive heart failure have different white blood cell differential cell counts than dogs without cardiac disease.

Materials and methods: In total, 72 dogs with congestive heart failure and 143 controls were included in this retrospective study. Signalment, white blood cell differential counts and echocardiography data were retrieved. Basic statistical analysis was performed on white blood cell differential counts, and principal component analysis was used to compare these counts between cases and controls, with age, gender and case/control status as supplementary variables. Cases and controls were compared with binary logistic regression for the principal components identified and individual white blood cell differential counts. Principal component analysis of cases alone was conducted with age, gender, weight and mitral E wave:isovolumic relaxation time as supplementary variables. Linear regression analysis was used to explore the association between mitral E wave:isovolumic relaxation time and the principal components, weight, gender, age and diagnosis (mitral valve disease or dilated cardiomyopathy).

Results: Among cases and controls, the largest variance in data (component 1) was associated with neutrophils, band neutrophils, monocytes and case status (P<0·01). The odds of an individual being a case increased 2·5-fold (95% confidence interval: 1·4 to 4·4) for each unit increase in component 1. Among the cases, mitral E wave:isovolumic relaxation time was associated with neutrophil count and case/control category.

Clinical significance: Dogs with congestive heart failure had a statistically significant increase in neutrophils, band neutrophils and monocytes in comparison with those without cardiac disease but the cell counts remained within normal reference intervals.