Efficacy of an extended-release tilmicosin preparation and tulathromycin in the treatment of bovine respiratory disease

A trial to evaluate the treatment of bovine respiratory disease (BRD) was established with tulathromycin (Tul-group) and tilmicosin (Til-group). This latter antibacterial drug is pharmaceutically prepared for 8-10 d sustained release. The challenge was carried out with spontaneously BRD-affected bulls, divided into Til-group (ɳ=44) and Tul-group (ɳ=50). Bulls were treated only once with either antibacterial drugs. Bacteriological analysis, arterial and venous blood chemistry, gasometrical parameters, and body temperature were obtained before and after treatment. The clinical cure rate was registered on days 7, 15, and 30. No mortality was observed. Clinical cure was statistically undistinguishable on these days (P> 0.05), and in both groups, all animals were considered healthy until day 30. Only customary pathogens were isolated i.e., Mannhemia hemolytica 38.88% (70/180), Pasteurella multocida 26.11% (47/180), Histophilus somni 18.33% (33/180, and Trueperella pyogenes 16.66% (30/180).