Mycoplasma species such as M. hyorhinis and M. hyosynoviae can cause clinical symptoms of arthritis in swine herds (Picture 1). These infections can lead to significant economic losses due to lameness, swollen joints, and poor growth.
Clinical M. hyorhinis tends to occur in swine from 3 to 10 weeks old and can cause polyserositis and pneumonia. M. hyosynoviae is mainly present in pigs over 3 months old. Although mycoplasmal arthritis has been identified for a long time, the number of clinical cases has increased in recent years. Vetmulin® / Rodotium® (tiamulin) has excellent activity against both pathogens.
High sensitivity to Vetmulin® / Rodotium®
Tiamulin MIC (minimal inhibitory concentration) values of globally isolated M. hyosynoviae and M. hyorhinis strains have been generated and published (Tables 1 and 2). These publications demonstrate low tiamulin MIC90 values and indicate an excellent sensitivity to Vetmulin® / Rodotium® in vitro.
Vetmulin® / Rodotium® provides high tiamulin concentrations in the synovial fluid of joints and in plasma following a single injection
After injections with Vetmulin® 162 mg tiamulin base/ml, tiamulin synovial fluid concentration levels rise above the MIC90 of M. hyosynoviae and M. hyorhinis very quickly (Figure 1). Therapeutic concentrations are maintained over a period of 24 hours.
Forty young gilts seriously affected with M. hyosynoviae arthritis were injected for 3 consecutive days with 10 or 15 mg tiamulin hydrogen fumarate/kg body weight/day. Over 7 days, the treated pigs showed a significant reduction in lameness score (Figure 2; p < 0.01) and had significantly better weight gain in comparison with the untreated control group.
Vetmulin® 162 mg tiamulin base/ml Solution for Injection at 1.5 ml/20 kg body weight, when injected for 3 days, is an effective treatment for pigs affected with mycoplasmal arthritis.