Investigating the Effects of Flunixin Meglumine and Meloxicam on Humoral Immune Responses Against E. Coli and T. pyogenes in Postpartum Dairy Cows.

INTRODUCTION: Disruption of the endometrial barrier after gestation leads to devastating effects on the cow's reproductive system. However, the accumulating immune responses help repair and defend the endometrium against microbial infections. Nevertheless, excessive inflammation could lead to chronic inflammation and consequently result in reproductive issues. The administration of non-steroidal anti-inflammatory drugs (NSAIDs) can reduce the harmful effects of excessive inflammation, modulate the immune response, and improve reproductive indices in postpartum dairy cows. The aim of this study is to evaluate the side effects of NSAID administration on humoral immune responses, which could potentially inform the development of more effective treatment strategies for postpartum cows. MATERIALS & METHODS: The study involved a total of 60 apparently healthy cows, which were divided into three groups Flunixin meglumine, meloxicam, and control. The test groups were treated at 3 and 8 days after calving. To assess the humoral immune responses, the IgG and IgM titers against Escherichia coli and Trueperella pyogenes, were determined on day 4, 9, and 15 after gestations. RESULTS: The results of the study showed that the drugs did not significantly affect the total specific and nonspecific antibody levels against tested pathogens. A time-dependent decrease and increase in the levels of IgM and IgG antibodies against E. coli and T. pyogenes were observed in all groups. CONCLUSION: The results showed a reduction in IgM and IgG titers against both pathogens after treatment with meloxicam and flunixin, respectively. However, the elevation of IgG and IgM titers suggested that the treatment affected antibody isotype switching rather than suppressing humoral immune responses.