Re-emergence of swine dysentery reinforces need for biosecurity

By Caleb Schaeffer

Swine marketing manager, Neogen Corporation

Barely a blip on the radar five years ago, swine dysentery is now increasing in prevalence and in concern.

The disease, commonly caused by the bacterium Brachyspira hydodysenteriae, is transmitted by contaminated feces, or carrier organisms such as birds and flies. It causes diarrhea in pigs, which often is bloody and contains mucus. Other diarrhea-associated symptoms follow, including weakness, dehydration and weight loss, according to information from Iowa State University’s (ISU) College of Veterinary Medicine.

If left untreated, it can lead to the death of the animal.

It also can have economic effects as it can lead to decreased feed conversion, adjustments to farm operations and the cost of medication, according to a presentation given by Dr. Jeremy Pittman.

The disease used to be a big problem in the 1990s – in fact, in 1994, it cost the swine industry almost $115 million. Improved production methods and the recognition of how dysentery is transmitted virtually wiped it out, according to

There were only a few cases of swine dysentery reported to the ISU veterinary diagnostic lab in 2003, but 2011 saw about 100. This year is shaping up to have about the same number of cases as last year, reported.

It’s an illness with huge biosecurity implications as the bacteria can live up to two months in lagoon water or damp feces, and in the dirt for more than two weeks. It can also be spread by mice, dogs, birds, flies and fomites, or inanimate objects such as a bucket or a brush. Given this, proper cleaning and disinfection procedures are key to preventing an outbreak before it happens. Your consulting veterinarian may want to perform a differential diagnostics test as there are multiple pathogens capable of producing dysentery in your herd. These pathogens include:

  • Lowsonia intracellularis (proliferative enteritis)
  • Trichuriasis (whipworm infection)
  • Gastric ulcers
  • Spirochetal colitis (B. pilosicoli)
  • Salmonellosis

Remember to consult a veterinarian to make a diagnosis and to discuss treatment options for the herd.

Preventing swine dysentery

Firstly, it’s important to ensure newly purchased pigs come from a herd that is negative for swine dysentery. The animals also should be quarantined for 30 to 60 days before being introduced into the herd, according to the information from ISU.

Next, swine producers must ensure the proper cleaning and disinfection of surfaces and fomites, as both can transmit the bacteria to otherwise healthy animals. Prior to disinfecting, the objects or surfaces must be cleaned (that is, removing obvious debris, dirt, feces, etc.), which will allow the disinfectant to work properly. Water alone won’t do the trick. Specialized cleaning products should be used.

After the objects or surfaces are cleaned, a disinfectant should be used to kill microorganisms, including B. hydodsyenteriae. There are a number of disinfectants available, all with different purposes and target organisms. Please consult with a veterinarian or product supplier to determine which disinfectant to use.

Proper insect and rodent control also are important as the bacteria can live in mice for more than 180 days. A pest control program should be discussed with a veterinarian and a product supplier to ensure implementation of an effective rodent and insect control plan.

For a list of Neogen’s cleaning and disinfecting products, click here.

For a list of Neogen’s pest rodenticide and insect control products, click here.

For other Neogen blog posts regarding biosecurity, click here.

Comments are closed.