Background and history

This is a condition often considered a sequel to rectal prolapse. Approximately a fingers length inside the rectum the tissues gradually shrink, scar tissue develops and eventually the tube completely closes. Affected pigs in the early stage of the disease often show a very loose diarrhoea that becomes projectile and a gradual increase in the size of the abdomen, with loss of condition.

The area where the stricture occurs is supplied by two tiny arteries that originate from the aorta. Some studies suggest that if these arteries are blocked or thrombosed by bacteria a rectal stricture will result. Erysipelas, Haemophilus parasuis, streptococci and salmonella have been implicated. If rectal strictures occur in large numbers at predictable times consider infection as a cause and assess the effects of strategic medication by injection, water or in-feed.

Clinical signs

Weaners and growers

Affected pigs in the early stage of the disease often show:

• A very loose watery diarrhoea that becomes projectile.
• A gradual increase in the size of the abdomen.
• Constipation.
• Loss of condition / poor growth.

Sows and piglets

• N/A

Diagnosis

This is based on the clinical signs

Causes

• Infection and thrombosis of blood vessels.
• Sequel to rectal prolapse.

Prevention

• Determine if there is a recurring time period when this first appears.
• Approximately three weeks prior to this look for trigger factors.
• If more than 2% of growing pigs are affected apply in-feed medication at the predetermined time and assess the results. 500g of OTC per tonne for two weeks may prevent the condition if an infection such as Haemophilus parasuis is the predisposing cause.
• Consider all the factors outlined for the control of rectal prolapses.
• Ear tag rectal prolapses to see if they develop into strictures, often they do not.
• Replace all rectal prolapses immediately, suture and see whether this affects the incidence.

Treatment

There is no treatment for this condition and as soon as pigs are recognised they should be destroyed on welfare grounds. Attempting to open up the stricture by palpation has in the author's experience been a total failure.