Identifying, Treating, and Preventing Swine Dysentery 

Swine dysentery in pigs causes diarrhea, often with blood in the stool

Swine Dysentery 

Swine dysentery (SD) is a highly infectious disease caused by the bacteria Brachyspira hyodysenteriae. It causes diarrhea, often with blood in the stool. A loss of body weight, and listlessness, also accompany SD. This disease wreaks havoc on pig farms and is responsible for severe economic losses from infected herds (that must be isolated and receive costly medications). 

This organism thrives in cool and moist environments, and once the bacteria infects the pig, it breeds in their colon. The pig suffers from severe diarrhea and inflammation of the large colon. 

Humans aren’t affected by the Swine dysentery bacteria. However, they can carry the bacteria on their boots or clothing and pass it on to the pigs. Pigs of all ages can be infected with SD. However, it’s rarely seen in piglets under three weeks old.

Causes of Swine Dysentery

The leading cause of Swine dysentery is when pigs ingest contaminated feces. This bacteria can survive up to 2 months in moist feces. It’s essential to keep your pig’s living environment clean to avoid the spread of bacteria. Therefore, scrub your pig sties weekly with a strong disinfectant. 

Infected rats and mice can also carry this disease to your pigs. Other ways that this disease can be transmitted are by birds, flies, and mites. Carrier pigs can have the disease and spread it for almost 90 days.

Symptoms of Swine Dysentery

Pigs with swine dysentery often have wasting syndrome. They stop growing or lose weight, look lethargic, and may have blood in their stool. Pigs are often hunched, look haggard, and have sunken eyes or twitching tails. They will look ill. 

  • Yellowish-gray diarrhea that has a slimy coating or mucus
  • Fresh blood is present in the stool
  • Fecal material may ooze out of the anus and cover your pig’s hind legs
  • Twitching tail
  • Hunched over 
  • Haggard appearance
  • Sunken eyes
  • Loss of appetite
  • Severe cases can lead to sudden death

Treating Swine Dysentery

The infected pig or herd should be in quarantine for at least 30 to 60 days to avoid spreading the disease. Antibiotics such as Carbadox, Tiamulin, and Lincomycin need to be administered. Unfortunately, antibiotic resistance is increasing, which makes a long-term strategy difficult. 

Keep your pigs’ living area clean, and disinfect their pens regularly to avoid the growth of bacteria and further spread of the disease. Currently, there is no vaccine available for this disease. You will need to rely on antibiotics and preventative measures to keep this disease under control.


Iowa State University College of Veterinary Science Swine Dysentery and Spirochaetal Colitis

Talitha van Niekerk

Hi, I’m Talitha van Niekerk, and I made the leap to farm animal ownership when I decided to fulfil my lifelong passion to own horses. Now, over a decade later, I run a public stable facility on 180 acres of land, caring for over 75 horses of all breeds and sizes. I love to write about my experiences, sharing the knowledge I have gained and helping others achieve their life’s passion to live on the land. See my about page here.

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