Surveys have shown that between 86 percent and 96 percent of U.S. swine herds test positive for the bacteria responsible for causing ileitis – Lawsonia intracelularis. Estimates suggest that 50 percent to 60 percent of those herds will experience symptoms of the disease within a 12-month period.

“Outbreaks are difficult to predict, treat or control. They’re also costly to the producer,” says Nathan Winkleman, DVM Swine Services Unlimited, Morris, Minn. He has conducted extensive research on ileitis and other enteric swine-disease challenges.

He believes that the acute form of the disease (porcine hemorrhagic enteropathy) is more common today than it was five years ago. “Part of it is that practitioners are more aware of PHE and its symptoms of acute bloody scours and mortality.”

A PHE diagnosis is relatively easy to make in finishing pigs and young breeding stock, as black, tarry diarrhea and sudden death of high-health animals in a pen are the clues.

Among other things, chronic ileitis can reduce average daily gain by up to 35 percent and cut feed efficiency by as much as 20 percent. Industry impact from ileitis could equal as much as $1.7 billion, or $22.19 per pig (based on an 86 percent infection rate), according to a 1998 research report from the International Pig Veterinary Society.

Winkleman points to five specific risk factors that predispose pigs to ileits:

1) Co-mingling groups of pigs.

2) Overheating and/or chilling pigs.

3) Transportation stress.

4) Repopulation– partial or total.

5) New buildings.

“Ileitis episodes typically occur two weeks after pigs encounter one or more of these stresses,” says Winkleman. “Anything managers can do to reduce stress will help minimize clinical signs of ileitis.”

Treatments are available and it’s best to consult with your veterinarian. But prevention has and continues to be your best option.