Efficacy Evaluations of the Use of Oral Tilmicosin in Pneumonic Calves

The therapeutic effect of oral tilmicosin was compared with enrofloxacin, and the efficacy of three doses of the drug was examined in two fully randomized blinded field trials. Pneumonic milk-fed calves between 3 days and 2.5 months of age were allocated into two groups in trial 1 (50 animals) and into three groups in trial 2 (69 calves). In the first trial, the animals were treated with 25 mg/kg/day tilmicosin or 2.5 mg/kg/day enrofloxacin in milk for 5 days. In the second trial, the calves received either 25 mg/kg/day tilmicosin for 5 days or 3 days, or else 12.5 mg/kg tilmicosin for 5 days. All calves were clinically examined for 10 days. In the first trial, oral tilmicosin at a dose of 25 mg/kg/day for 5 days proved to be effective for the treatment of endemic pasteurellosis of milk-fed calves. The efficacy was the same as that of enrofloxacin. All three doses in the second trial were effective and were statistically equivalent to the original dose tested.