Long-term impact of puerperal metritis on the profiles of peripheral blood leukocytes in peripartum dairy cows.

To determine the effects of puerperal metritis on the immune response, changes in the differential peripheral blood leukocyte counts were analyzed during the peripartum period in cows with or without metritis. Multiparous Holstein cows were examined for uterine health disorders and classified into two groups: healthy (n = 11) or metritis (n = 5) cows. The lymphocyte and monocyte counts and the proportion of CD8(+) lymphocytes were higher in cows with metritis compared to healthy cows. Moreover, the effects of puerperal metritis on the lymphocyte counts and CD4(+)/CD8(+) ratio persisted weeks after the uterine inflammation had self-resolved. Taken together, the findings of the present study indicate the possible long-term alterations of systemic immune responses in cows with puerperal uterine inflammation.