Nasopharyngeal swabs were collected from 100 lambs aging 9 -12 months (30 healthy and 70 pneumonic lambs for bacteriological examination. Overall, 25% were positive for P multocida. Antibiogram study of the isolates revealed that marbofloxacin was the highest effective against P. multocida. Forty lambs (20 healthy and 20 naturally infected with P multocida) were divided into 8 groups (5, each), the 1^st group: healthy lambs (control), 2^nd group: healthy received marbofloxacin, 3^rd group: healthy received flunixin meglumine, 4^th group: healthy received marbofloxacin and flunixin meglumine together, 5^th group: infected non treated, 6^th group: infected treated with marbofloxacin, 7^th group: infected treated with flunixin meglumine and 8^th: group infected treated with marbofloxacin and flunixin meglumine together. Hemato-biochemical changes at 1^st, 7^th and 14^th day post treatment were studied. All clinical sign disappeared and P.multocida microorganisms were not reisolated in group post treated by marbofloxacin alone or together with flunixin meglumine. Healthy lambs received marbofloxacin or flunixin meglumine either alone or together showed significant decrease in RBCs, Hb, PCV%, T protein, albumin, globulin, α, β, γ globulin and significant increase in WBCs, AST, ALT, ALP, GGT, urea and creatinine at1^st and 7^th day post injection. Pneumonic lambs showed significant reduction in RBCs, Hb, PCV% T. protein, albumin, total globulin, α, β globulin and significant increase in WBCs, AST, ALT, ALP, GGT, γ globulin, urea and creatinine all over the experimental period. Pneumonic lamb treated with marbofloxacin alone or with flunixin meglumine resulted in complete disappearance of these clinical signs at 1^st day post treatment but these clinical signs remained in flunixin meglumine alone lambs. It is concluded that, pasteurellosis in lambs resulted in adverse effect in hematobiochemical parameters. Using marbofloxacin alone or together with flunixin meglumine in treatment of diseased lambs lead to improve clinical signs and hemato-biochemical parameters at 7^th day post treatment.