The objective of the present study was to determine erythometric and leukometic values and quantify subpopulations of lymphocytes in umbilical cord blood (UCB) and jugular blood of neonate foals. UCB and jugular blood were collected from 20 foals at birth and processed for determination of erythometric and leukometric values and quantification of subpopulations of T lymphocytes by cytofluorometry. No significant difference (P<0.05) was noted between average values in neonate jugular blood and equine UCB. Total values observed for segmented neutrophils in UCB and neonate jugular blood were lower than those reported for horses at birth. The quantity of CD5+ and CD4+ lymphocytes was lower in UCB and neonate jugular blood than in peripheral blood of adult horses, which indicates immunological immaturity. The frequency of CD8+ lymphocytes, however, was similar to that described for peripheral blood of adult horses. CD4:CD8 ratio observed in the present study both for UCB (2.64±0.91) and for neonate jugular blood (2.41±0.81) demonstrated the predominance of CD4+ T lymphocytes over CD8+ T cells.
immunophenotyping; cytofluorometry; neonates
