Treatment of pigs experimentally infected with Mycoplasma hyopneumoniae, Pasteurella multocida, and Actinobacillus pleuropneumoniae with various antibiotics

The authors have performed a comparative study of the efficacy of various i n-feed medications for the treatment of 5- to 6-week-old specific pathogen- free (SPF) piglets experimentally infected on day 1 with Mycoplasma hyopneu moniae, on day 8 with Pasteurella multocida (serotype A), and on day 15 wit h Actinobacillus pleuropneumoniae (serotype 2). The treatment started on da y 9 and continued for 12 consecutive days, then the piglets were euthanized for examination of macroscopic, histologic, and pathologic lesions and for the presence of mycoplasmas and bacteria in the lungs. Based on the result s of clinical observations (respiratory signs, rectal temperature, body wei ght gain, and feed conversion efficiency), macroscopic and histologic lesio ns of the lungs, and microbiologic findings, the best results were obtained by treatment of pigs with Econor + chlortetracycline, followed by Tetramut in, Pulmotil, Cyfac, and lincomycin + Chlortetracycline.