Pathological studies on some antibiotics administred for treatment of chronic diseases

The present work was designed to study the pathologicallesions induced by experimental colibacillosis and mycoplasmosis and to investigate the efficiency of Danofloxacin and Tilmicosin against these lesions.One hundred and ninety two broiler chicks of 2 week old ages were divided into 8 groups (24 chicks for each group).Infection with E.coli in group (1) showed depression,anorexia, ruffled feathers, weight loss during the first 2 weeks post infection (PI). Poor growth and labored rapid breathing with gasping were observed, later on (3-6 weeks PI). Macroscopically, the experimental chicks which were sacrificed, 1 and 2 weekpericardial sac, hepatic capsule and airsacs were also detected.The trachea showed congested mucosa. The intestine was markedly distended with fluid and mucoid yellowish browncontent. Microscopically, liver and heart showed congestion ofthe hepatic blood vessels with thickening of hepatic capsule andPericardium, airsacs with serofibrinous exudate and lymphocytesinfiltration, trachea showed Catarrhal tracheitis. The lung showedcongestion of pulmonary blood vessles with catarrhal bronchitisand intestine showed coagulative necrosis and sloughing in theintestinal villi.Infected chicks with Mycoplasma in group (2) showed lossof appetite, depression, respiratory signs within the first 2 week