Tilmicosin phosphate is a macrolide antibiotic synthesized from tylosin,It developed for veterinary use only.and it has an antibacterial spectrum similar to tylosin with enhanced activity against Pasteurella haemolytica, P. multocida, Actinobacillus pleuropneumoniae, mycoplasma species and other microorganisms found sensitive to this compound. It is recommended for treatment and prevention of pneumonia in cattle, sheep,poultry and pigs, Not show resistance and cross-resistance with other antibiotic often used in clinic. Mainly used in the Pleuropneumonia and the infection caused by Pasteurellaceae , Pasteurella and mycoplasma.