Samples from cloacal swabs, liver, heart, lungs, trachea, spleen and nasal exudate were collected from 150 pekin duckling aging 1-30 days (75 apparentaly healthy 35 diseased and 40 freshly dead) for bacteriological examination. Out of 150 examined sample 43 (28.67 %) were positive for Pasturalla miltocida. P. miltocida distributed as 5 from apparentally healthy, 13 from diseased and 25 from dead duckling. Antibiogram study of isolates revealed that florfenicol was the  highest drug effective against P. milt .
A total of 160, one day old pekin duckling (80 healthy & 80 experimantally infected with P miltocida.) were divided into 4 equal groups ( 40 birds each), the 1^st group consisted of healthy duckling (control), the 2^nd group inculded healthy duckling treated with florfenicol (30mg/kg bwt.) in drinking water for 5 days, the 3^rd group inculded infected non treated and the 4^th group inculded infected duckling treated with florfenicol (same dose, period and rout of administration). In the four groups the hemato-biochemical changes were studied.
 The results revealed that healthy pekin duckling treated with florfenicol displayed significant rise in body weight, leukocytic count, lymphocytes, significant decrease in heterophils and insignificant increase  in monocytes, eosinophils, basophils, total proteins, albumin, globulins, A/G ratio, AST, ALT, ALP, uric acid and creatinine.
Pasteurellosis in duckling induce anorexia depression, ruffled feather, coughing, diarrhea, mortality rate 30%, rise respiratory rate, monocytes, total, β, γ globulin, AST, ALP, uric acid, creatinine levels and significant decrease in weight gain, heterophils, albumin, α globulin, A/G ratio, insignificant decrease in leukocyte, lymphocyts, esinophils, total protein and insignificant rise ALT
 Florofenicol residue in examined liver and kidney in both healthy and diseased duckling treated with florofenicol were high at 1^st day post treatment, very low at 6^th day and  completely disappeared from examined samples at 9^th day post treatment The highest levels of florofenicol residues were recorded in the kidneys then liver.
Duckling suffering from pasteurlosis and treated with florfenicol showed no clinical signs, decrease mortality rate to 5%, reduced re-isolated P. milt and Improve hemato-biochemical parameters.
It could be concluded that florfenicol is effective against P. miltocida in duckling