Efficacy of Vetmulin® / Rodotium® (Tiamulin) in controlling Mycoplasma suis infections

Lieven Claerhout DVM

Mycoplasma suis attaches and penetrates the erythrocytes and therefore leads to haemolytic anaemia. The organism has an enormous impact on rendability due to the impaired oxygen transport capacity in pigs.

This mycoplasma species, which is distributed worldwide, can be transported via blood sucking arthropods, injection, surgical castration, urine, saliva, and nasal and vaginal exudates. Intra-uterine infection of piglets may also be possible. A study in Germany revealed that piglets were infected in 40.3% of the 196 tested farms. However, this infection is often not included in the differential diagnosis and its impact is underestimated. A commercial vaccine is not available.

 

Field trial

  • High health commercial herd housing 600 sows
  • 4-week batch farrowing system

 

Clinical symptoms

  • Sows
    • Reduced milk production
    • Impaired fertility
  • Suckling and weaning pigs
    • Pale skin colour despite an intramuscular iron injection on day 3
    • Significantly lower technical performance: poor growth
    • More secondary infections like diarrhoea and Streptococcus suis infections

 

Diagnosis M. suis

  • Clinical symptoms
  • Blood analyses
    • Qualitative PCR tests
    • Very low haemoglobin content in the blood of 16-day-old suckling piglets (4.8 mmol/l)
  • Culture and serology are not possible

 

Treatment

  • Group treatment: all present sows and gilts in quarantine
  • Vetmulin® / Rodotium® Premix at 10 mg tiamulin hydrogen fumarate / kg bodyweight / day for 14 consecutive days in feed

 

Measured parameters before and after treatment

  • Haemoglobin values of the piglets (Figure 1)
  • Technical parameters of the weaned pigs (day 20 to 69 after birth) of the first 4 groups after treatment (n=6520) compared to the last 4 groups before treatment (n=6843; Figures 2, 3 and 4)
  • M. suis PCR blood analyses

 

Figure 1. Day 16 haemoglobin content (mmol/l) before and after treatment

Figure 2. Pre-weaning mortality (%) before and after treatment

Figure 3. Weight at weaning (kg) before and after treatment

Figure 4. Average daily gain (g/day) in the nursery before and after treatment

 

Three months after treatment, no positive results were found when performing a total of 20 PCR blood analyses of sows, gilts, and weaned pigs. 

 

Conclusion

M. suis infections have an enormous impact on the technical performance of sows and piglets. This haemotrophic disease can be controlled by the administration of Vetmulin® / Rodotium® to affected sows. 

 

References are available on request