Immunological and Biochemical Profiles of Tilmicosin in Rabbits

This study aimed to evaluate the effect of tilmicosin on rabbit immunity after daily subcutaneous (S.C) injection for 3 successive days. Fifteen New Zealand male rabbits were divided into 3 groups; the first group was left as a control, the second was non treated vaccinated against pasteurellosis (1 mL S.C in the skin fold of the back of the rabbit), while, the third was vaccinated and treated by tilmicosin in a dose of 10 mg/kg BW daily for 3 days. Whole blood and serum samples were collected from each rabbit on 1st ,3rd ,9th ,14th ,21st and 28th days post drug administration to determine some immunological and biochemical parameters. Histopathological examination of liver, kidneys and heart of all groups was also carried out. The results revealed that tilmicosin elicited a significant increase in B-lymphocytes, nitric oxide production by macrophages and lysozyme activity of the serum. Meanwhile, the drug had no significant changes on alanine aminotransferase enzyme (ALT) and aspartate aminotransferase enzyme (AST) levels (liver enzymes). On the 21st day ALT showed significant decrease. Moreover; there were no significant changes on urea and creatinine levels (kidney functions) when compared with control group. Histopathological findings of the vaccinated and treated groups showed lesion score from 1st and 2nd degree. It could be concluded that tilmicosin afforded a good effect on rabbits' immunity without negative effects on liver and kidney functions.