Porcine Proliferative Enteropathy


Other names

Ileitis, PIA, Porcine Intestinal Adenomatosis, Red Gut. Porcine Enteropathy.

Causal agent

Lawsonia intracellularis an intracellular curved bacteria.

Age group

Acute form occur in young breeding stock or finishing pigs

Young growing pigs exhibit chronic forms of the disease

The disease, albeit not apparent, can affect 15 to 50% of the growing herd

Clinical signs

Acute Form

Proliferative haemorrhagic enteropathy



Death (often the first signs seen). Pale and anaemic animals. Depression, reduced appetite and reluctance to move. Retarded growth. Watery, dark or bright red diarrhoea. The hindquarters may be stained with bloody faeces. Abortion may occur in recovering animals often within 6 days of the onset of clinical signs. More often seen in young adults greater than 70 kg.

Chronic forms


More often seen in growing animals 20 to 70 kg. The clinical signs depend on the extent of the intestinal lesions.


Necrotic ileitis

Regional Ileitis

With Porcine intestinal adenomatosis (PIA) clinical signs can be very slight with irregular periods of diarrhoea and anorexia.

Animals with Necrotic ileitis have more severe clinical signs in individuals with severe loss of condition and often persistent scour. Death is not uncommon. Major effect is the increased FCR and thus feed costs necessary to finish the animal. In chronically affected herds, days to slaughter may be extended by up to 14 days

Animals with regional ileitis also present with severe loss of condition and sometimes a terminal peritonitis



The pigs are infected by oral contact with faeces from infected pigs and the disease can be shed for at least 10 weeks.

Nearly all farms have the organism present on the unit

Incubation period


The incubation period is 13 days



Examination of faecal samples for L. intracellularis by specific antibody stains

PCR (DNA) analysis of faeces for the bacteria. The bacteria does not grow in media. There are blood tests available

Histology of the intestine may be useful for presumptive diagnosis


Post-mortem Lesions

Post-mortem findings

Post mortem findings generally restricted to the terminal 50 cm of the small intestine and possibly just into the spiral colon and caecum.

PHE The small intestine and large intestines are dilated and filled with a formed blood clot. The colon contains black tarry faeces. The intestinal contents are rarely liquid. The intestines bulge out of the abdomen once opened.

PIA: The intestinal wall thickens often with oedema to varying degrees. The mucosa is thrown into folds and may result in sharply defined plaques or marked multiple polyp formation.

Necrotic ileitis: There is necrosis of the underlying PIA lesion resulting in yellow/grey cheesy masses that adhere tightly to the wall.


Regional ileitis: The lower intestine becomes thickened and ridged. Often referred to as hosepipe gut. Ulceration can be seen in the mucosa.



Oral vaccines can be very effective.

Antimicrobial therapy, Tylosin (Valnemulin) and Tiamutin very effective.

Wash and disinfect pens

Minimise mixing of pigs

Use all-in/all-out

Maintain proper pig density, water and feeder space

Maintain proper building temperature and ventilation

Match health history of incoming pigs to those of the farm

Reduce scrape through passageways

Common differentials


Intestinal twist, Haemorragic bowel syndrome, gastric ulceration, Swine Dysentery, Salmonellosis, Whip worms and chronic TGE

Salmonella - colon and focal ulcers and lymph node enlargement

Swine dysentery - large intestine only, without swelling of lymph nodes

Whip worms - pin point lesions in colon and adult worms in large intestine

Zoonotic Implications


Unsure. Lawsonia intracellularis has been recognized in other animals horses and hares.