A total of 29 lambs (1-1 .5 years old} w ith average body weigh t 30-40 leg (5 clinically healthy lamb and 24 pneumonic lambs ) were used in this investigation these lamp were belonged to a private from in sltarfcia Governorate ll1is studu aimed lo invesiigate .some hematological an biocltemical cltcmges associali11g it in lambs were d iv ided inlo lhree groups U re ji rsl group (5 lambs} was apparenilu JieaW1u and served as a control group U te pneumonic lambs were divided into lwo equal groups 12 lambs in each second group 12 lambs in each second group received Uterapeulic does of jl01fenicol lwo (IM} w ith 48/t interval between lltircl group re­ ceived ll ierapeulic close of gentw11vcin (11\1) for 5 successive clclus l1loocl sw11ples were collecled from each lamb bu j ugular vein punclure before treatment and 5, 10 and 20 claus post l reat11ientfor ltematological and some biochemical parameters cleler­ minalion.