Category:Enteritis, Fibrinous/Haemorrhagic

Pathology

• The mucosa eroded to produce lesions of darkish-red submucosa covered in dry, crumbly fibrin.
• Is usually caused by severe damage due to secondary bacterial infection following an earlier milder insult.
• Tends to be more severe in the lower small intestine and upper large intestine.
  • Many severe infections tend to get worse further down the gut.
    • Catarrhal change may be seen in the upper small intestine and fibrinous change in the lower small intestines.
  • In the lower aprt of the bowel, where the inflammation is more severe, disease is more anaerobic.
    • Lesions are caused by anaerobic organisms- convert mild diseases into more serious disease.

Salmonellosis

Swine Dysentery

Parvovirus Enteritis

Bacterial septicaemia and enteritis

• Some severe acute septicaemias cause very severe acute haemorrhagic enteritis with bleeding into the alimentary tract.
• Death is usually rapid.
• Fairly easy to diagnose
  • small intestine is full of dark, tarry, partly clotted blood (like black currant jelly).
• Associated with severe systemic disease, e.g.
  • Anthrax in cattle (Bacillus anthracis).
  • Leptospirosis in dogs.
    • Especially L. icterohaemorrhagiae.
• Do not confuse with warfarin poisoning.
  • Also gives blood in stomach and intestine BUT there are no signs of inflammatory disease.

Lamb Dysentery (Enterotoxaemia with Blood)

• Clostridium perfringens causes very severe acute haemorrhagic enteritis.
  • Usually affects young farm animals
    • May also be seen in pets.
• Type B Clostridium perfringens infection of lambs leads to lamb dysentery.

Clinical

• Lamb dysentery is usually seen in lambs under 2 weeks of age.
  • Related to being kept in a cold, dirty environment, with build-up of infection during the lambing season.
• Lambs may produce bloodstained diarrhoea before death, but they often die before this effect is apparent.
• Diagnosed by culturing contents of gut.

Pathology

Gross

• The gut is blown and distended with foamy ,bloody contents.
• Sometimes ulceration with perforation and fibrinousperitonitis is seen.
• Focal or diffuse congestion and haemorrhages.

Histological

• Coagulative necrosis of villi.
• Oedema.
• Haemorrhage.
• Influx of inflammatory cells in the lamina propria and submucosa.

Similar Conditions

• Piglets show similar disease caused by Clostridium perfringens type C (and sometimes type B)
  • May look similar to a volvulus but with no twist present.
• In adult sheep Clostridium perfringens type B infection causes Struck.
  • Enterotoxigenic gastritis.
  • Acute sudden death with haemorrhagic enteritis
  • Haemorrhagic enteritis is not as severe as in lambs, and tends to be more patchy.

Colitis X

• Affects the horse.
• Sudden onset with haemorrhages throughout body (shock) and sometimes acute foul smelling diarhoea.
• colon is acutely haemorhagic and oedematous with mucosal necrosis.
• Associated with Clostridium perfringens.
• Possibly an enterotoxaemia.