Spirochetes are common inhabitants of the large intestine and caecum and disease is often associated with changes such as the inadvertent removal of copper from the diet, withdrawal of growth promoters or a sudden change in diet.

Clinical signs

A mild to moderate diarrhoea develops two to six weeks post-weaning that persist for a few days with dehydration and loss in growth. Most cases resolve in 7 to 10 days but in some pigs chronic diarrhoea results. The disease can be difficult to differentiate from the bacterial infections, particularly colitis.

Diagnosis

This is difficult because specific organisms cannot usually be identified. If there is an on-going problem on the farm live diseased pigs showing typical signs should be submitted for post-mortem and bacteriological examinations to eliminate swine dysentery and demonstrate large populations of spirochetes associated with an enteritis.

Treatment

• In-feed medication. Lincomycin, tiamulin, monensin, dimetridazole and tylosin all have good activity against spirochetes and can be used for both prevention and treatment.
• In acute outbreaks lincomycin, tiamulin or tylosin could be used in the water.
• Inject individual pigs with either lincomycin, tiamulin or tylosin and assess the response.