ОСТРАЯ ТОКСИЧНОСТЬ И СРАВНИТЕЛЬНАЯ ТЕРАПЕВТИЧЕСКАЯ ЭФФЕКТИВНОСТЬ ЛЕВОФЛОКСАЦИНА ПРИ ЭКСПЕРИМЕНТАЛЬНОМ КОЛИБАКТЕРИОЗЕ ЦЫПЛЯТ

Abstract

Development and improvement of treatment modes for colibacillosis in chickens is very important as this disease is rather prev-alent in bird population. Fluoroquinolones are drugs that are very effective in treating bacterial infections, associated with Gram- negative microorganisms, in animals. The goal of the present research was to evaluate acute toxicity of Levofloxacin in chickens and to study its comparative therapeutic effi-cacy in experimental colibacillosis of chick-ens. For the experiment aimed at evaluating acute toxicity of Levofloxacin all the chick-ens were assigned to a total of 18 groups, 10 chickens were assigned to each group. The drug was administered by intraperitoneal injection at a dose of 100 to 950 mg/kg body weight. In our research median lethal dose (LD50) of Levofloxacin, in case of intraperi-toneal introduction to chickens, was as high as 470 mg/kg body weight (276.4–799 mg/kg body weight). For the experiment aimed at studying comparative therapeutic efficacy of Levofloxacin in experimental colibacillosis all the chickens were assigned to a total of 8 groups, 25 chickens were assigned to each group. In the course of the experiment every chicken was challenged with Escherichia coli, by intraperitoneal introduction of 150 million CFUs (E. coli had been cultured in suspension for 24 hours). Antimicrobial drugs (Levofloxacin, Enrofloxacin, Colistin, Ditrim, Doxycycline, Chloramphenicol) were first administered 24 hours before the challenge, at a concentration of 200 mg/L, via drinking water. The treatment continued 5 days. The chickens were monitored 3 weeks. The results of the experiments show the high therapeutic effect in cases of Levofloxacin (100%) and Enrofloxacin (92%). Administration of other antimicrobial drugs did not lead to the expected results. The survival rate was in the range 12 to 20%