Efficacy of one-shot Marbofloxacin treatment on development of porcine pleuropneumonia

Actinobacillus (A.) pleuropneumoniae is one of the main important respiratory tract pathogens in pork production. Because of no or limited cross protection between different serotypes the disease control by vaccination is mostly hampered. In consequence high levels of antibiotics are used for combating outbreaks and limit spreading of disease. As the responsible use of antibiotics is increasingly under official control, this study aimed to investigate the efficacy of a high dose one-shot treatment with a concentration-dependent antibiotic on disease progression and success of therapy.

For this study 36 pigs, aged 8 weeks, were infected in a standardized aerosol infection model. A. pleuropneumoniae serotype 2 challenge strain was used. All pigs entering the study were considered healthy by clinical and serological examination (Apx-II-ELISA). After development of clinical symptoms they were randomly divided into three treatment groups (T1: 8.0mg/kg bodyweight Marbofloxacin; T2: 2.5mg/kg bodyweight Enrofloxacin/day; T3: Saline 1ml/20kg bodyweight/day). Group T1 was treated once with active compound and with saline on the 2 following days; groups T2 and T3 were treated on three consecutive days. Afterwards the success of therapy was blindly assessed regarding lung lesions, bacteriological and clinical cure.

Eight pigs of group T3 and one of group T1 were removed due to severity of disease. There were no significant differences between T1 and T2 regarding bacteriological cure and extent of lung lesions on day 6 after infection; both were superior as compared to group T3 (P< 0.0001). Six days after infection there were significant differences between group T1 and T2 and group T1 and T3 regarding clinical cure and course of disease. In group T1 and T2 respiratory symptoms returned to normal within 24 hours and 48 hours after treatment, respectively (P= 0.01). On day 6 after infection 90.9% of the pigs of group T1, 83.3% of group T2 and 9.1% of group T3 were considered to be clinically healthy (T1:T3 = P < 0.001; T2:T3 = P < 0.001).

This study confirms that a single injection of 8mg/kg bodyweight Marbofloxacin was as efficacious as a three day treatment with a licensed reference product and superior to a negative control group based on clinical and bacteriological cure. Therefore the one shot treatment with 8 mg/kg Marbofloxacin is an excellent alternative for the treatment of porcine pleuropneumonia.

Disclosure of Interest: None Declared.