Category:Stomach and Abomasum - Inflammatory Pathology

• Gastritis refers to inflammation of the stomach.

Gastritis, Catarrhal

Oedema Disease In The Pig

Category:Gastric Ulceration

Fibrinous/ Diptheric Gastritis

• Not very common, but has severe consequences.
• Dirty-white, crumbly fibrin is seen on the surface of mucosa.
• Causes
  • Toxic
    • From drinking battery acid or other caustic material.
      • Also gives with stomatitis and oesophagitis as well.
    • Poisons such as mercuric chloride and carbolic acid also cause fibrinous/ diptheric gastritis.
  • Severe systemic disease
    • e.g. septicaemic Erysipelas and Swine Fever in pigs, or septicaemic Salmonellosis.
    • Not usually a primary problem but part of more severe generalised disease problem.

Haemorrhagic Gastritis

Clinical

• Usually only seen post mortem.
• Stomach full of thick tarry clots.
• Occasionally will vomit blood in life.

Pathology

Haemorrhagic gastritis (Courtesy of BioMed Image Archive)

Gross

• Wall of stomach is blacked and ulcerated.
  • Red, thickened, necrotic, haemorrhagic mucosa.

Histologically

• Coagulative necrosis with fibrin, oedema, haemorrhage, and sometimes emphysema.
• May extend deep into submucosa/muscle.

Pathogenesis

• There are several causes of haemorrhagic gastritis
  1. Aspirin and non-steroidal anti inflammatory drug toxicity.
  2. Peracute / acute infections, e.g.
     • Swine Fever
     • Anthrax
     • Leptospirosis in dogs (Leptospira icterohaemorrhagiae).
  3. Clostridial disease
     • e.g. Braxy (Clostridium septicum)
       • Affects older lambs or yearlings producing sudden death.
       • Usually seen on sheep grazing on frosted grass so more common in colder areas.
       • Bacterial exotoxin causes acute abomasitis.
       • Pathology- At post mortem the stomach is grossly distended with partially clotted blood. The wall of the stomach is thickened,reddened and oedematous.
       • Diagnosed by isolation of organism from the stomach wall.
       • Is now usually vaccinated against (Heptovac 7 in 1 clostridial vaccine).
  4. Warfarin poisoning.

Vesicular Gastritis

• Is not seen, as the stomach has no stratum spinosum.

Chronic gastritis

• Chronic gastritis is usually proliferative rather any other type of gastric inflammation.
• Usually a parasitic cause.
• Occurs mostly in the pig and in cattle.

• Pig
  • Redworms (Hyostrongylus)
  • Seen mostly in sows, and are present in up to 30% of pig herds.
  • Small numbers produce little pathology, but large numbers cause thin sow syndrome.
    • Animals eat well but slowly lose condition.

• Cattle
  • Ostertagiasis produces a condition similar to thin sow syndrome.

Chronic Hypertrophic Gastritis In The Dog

• Clinically see anorexia, weight loss, anaemia and associated hepatic disease.
• Associated with protein loss into gut.

Pathology

• Hyperplasia of mucosa.
  • Mucosa thrown up into folds.
  • Reduced numbers of parietal cells and increased numbers of goblet cells.

Chronic Atrophic Gastritis In The Dog

• Aetiology uncertain.
• Grossly: (may be difficult to appreciate)
  • Reduced mucosal thickness.
  • Loss of rugae.
• Histologically
  • Mucosal thinning.
  • Loss of gastric glands.
  • Diffuse inflammatory infiltrate of lymphocytes and plasma cells.
  • Fewer eosinophils in lamina propria.