ABSTRACT
BACKGROUND: The efficacy of a water soluble formulation of tylvalosin (Aivlosin® 625 mg/g granules) was evaluated in the treatment and metaphylaxis of Enzootic Pneumonia (EP) in pigs. In all four trials, pigs in the tylvalosin group were administered 10 mg tylvalosin/kg bodyweight in drinking water daily for 5 consecutive days (TVN). In a single-challenge study, pigs were inoculated with lung homogenate containing Mycoplasma hyopneumoniae. In a dual challenge study, pigs were sequentially inoculated with pure culture of M. hyopneumoniae and Pasteurella multocida. Efficacy was evaluated based on reduction of lung lesions compared to unmedicated control pigs (CTL). In two field studies at European commercial farms with confirmed outbreaks of EP, treatment efficacy in clinically affected fatteners was evaluated based on improved clinical conditions compared to pigs treated with tylosin at 10 mg/kg by injection for 3 consecutive days (TYL). In these field trials, healthy in contact pigs were enrolled for metaphylaxis efficacy evaluation based on reduction in incidence of new clinical cases of respiratory disease compared to unmedicated pigs (CTL). RESULTS: In the M. hyopneumoniae-only challenge study, pigs in TVN group had lower lung lesion scores than CTL (6.52 vs. 14.97; p < 0.001). In the dual challenge study with M. hyopneumoniae and P. multocida, pigs in TVN group had lower lung lesion scores than CTL (3.32 vs. 8.37; p < 0.01) and the recovery of both challenge bacteria from the lungs was lower in TVN compared with CTL group (p < 0.01). In field outbreaks of EP, multicentre analysis showed that 13 days after the start of medication, treatment success for TVN pigs was significantly better than for TYL pigs (80.0% vs 48.7% p = 0.03) and metaphylactic administration of TVN significantly reduced the incidence of new clinical cases (2.1% vs. 7.8%; p < 0.01) compared with unmedicated controls. CONCLUSIONS: Tylvalosin at 10 mg/kg daily for 5 days in drinking water was safe and effective in the treatment and metaphylaxis of EP in pigs associated with infections of M. hyopneumoniae either alone or in combination with P. multocida under both experimental challenge and field natural infection conditions.
ABSTRACT
This study was designed to evaluate the efficacy of a new florfenicol/meloxicam combination (FMC) in calves with bovine respiratory disease. A total of 90 young calves were challenged via intratracheal deposition of 108 colony-forming units of Mannheimia haemolytica Data for 84 calves demonstrating a rectal temperature (RT) above 39.5°C and a combined total clinical score (TCS) greater than or equal to 3 were included. Calves were then randomly allocated to one of the three study groups (FMC; florfenicol/flunixin combination (FFC); or saline) and promptly treated. RT and TCS of calves treated with an FMC or FFC were consistently lower than RT and TCS of calves belonging to the control group (P<0.001). Moreover, at the end of the study, a high clinical cure rate was observed in calves treated with FMC (100 per cent) or FFC (96.6 per cent) whereas cure was limited for calves receiving saline (29.6 per cent). Interestingly, calves treated with FMC were cured without relapse more rapidly compared with calves treated with FFC (HR=1.76, P<0.05) and with a lower percentage of clinical relapse due to fever (P=0.05). These results underline the high efficacy of the FMC and are in line with the pharmacokinetic properties of florfenicol and meloxicam.