Immunophenotypic evaluation of working Labrador Retrievers and German Shepherd dogs living in the same environment

Multiparametric flow cytometry was used to compare peripheral blood lymphocyte subset distribution between healthy working police Labrador Retrievers (LRs; n = 12) and German Shepherd dogs (GS; n = 11) living in the same environment. The CD4/CD8 ratio was significantly higher in LR than in GS because of the lower percentage of CD8+ T lymphocytes in LR. GS showed the highest relative percentage of CD3−/CD21− lymphocytes, whereas LR had the highest percentages of MHC II+ lymphocytes. Because age, sex, environmental and housing conditions, dietary patterns, and training or working routines were similar in both breeds in the study, differences in peripheral blood lymphocyte subset distribution could be attributed to the influence of breed on the immune system.