Animal Health - the gut

• The gut 'tube'

  Long tube from mouth to anus, joins with skin, lined with mucosa, facilitates digestion & protection
• The gut structure

  • A tube with 4 basic layers: Serosa, Muscularis (outer + inner layer), Submucosa, Mucosa
• The gut protection - epithelial cells help in

  Secretion, absorption and distribution of hormones, enzymes and fluids
• Gut functions: Process food to

  1. Obtain nutrients + remove waste

  2. Transport nutrients for further use

  3. Maintain integrity, body functions and health
• Gut functions: Protect damage from

  1. Invaders

  2. Food

  3. Pathogens
• Mechanisms of gut protection

  • Sensory
  • Physical + mechanical
  • Biochemical + physiological
  • Phagocyte cells & immunity
• Gut protection: 5 senses - indirect

  • Sounds - early warning
  • Sight - stimulate or suspend
  • Smell - stimulate or suspend
• Gut protection: 2 senses - direct

  • Touch / feel (lips, mouth)
  • Taste (tongue + taste buds)
• Gut protection - physical & mechanical - against large particles

  Teeth, jaw + tongue - reduce size + soften, cutting + disintegration, grinding + regurgitation
• Gut protection: physical + mechanical - Gut reduces particle size - stomach

  1. Churning, mixing, softening

  2. Propulsion via pylorus to duodenum

  3. Retropulsion - push larger particles back

  4. Grinding + propulsion by proximal stomach
• Gut protection via peristalsis

  1. Vomiting & diarrhoea

  2. Gut distension & impaction (constipation)

  3. Gut rupture + peritonitis
• Gut protection (biochemical, physiological) Oral cavity

  1. Saliva pH - neutralise

  2. Enzymes - chemical disintegration

  3. Mucous - lubrication, lysozyme - antiseptic
• Gut protection (biochemical, physiological) microbes

  • Pathogens: moulds
  • Metabolites: toxins, poisons, lectins
• Gut protection (biochemical, physiological) stomach

  • ACID - kills pathogens, disintegrate food, inactive toxins
  • PEPSIN - for proteolysis
  • HORMONES - for start/stop
  • MUCOUS - lubrication, food softening
• Gut protection (biochemical, physiological) small intestine (Duodenum, Jejunum, ileum)

  • Enzymes for chemical breakdown
  • Lymph & Mucous for gut protection
  • Antigenic or Mast cells
• Gut protection (biochemical, physiological) Large intestine (Caecum, colon, rectum)

  • Microbial, mucous & lymph: inactivation of pathogens, binding + disintegration, metabolites & elimination
• Gut protection - gastric diffusion barrier - Epithelium

  Epithelium has cell tight junction in glands - impermeable to acid of gastric membrane
• Gut protection - mucous gel layer over epithelial cells, Composition

  • Mucin (a high molecular glycoprotein)
  • Phospholipids
  • Electrolytes
  • Water
• Gut protection - mucous gel layer over epithelial cells, function

  • Responds to antigenic stimuli
  • Lubricate to prevent abrasion by luminal food
  • Viscous covering that protect gut injury from acid, bile, ethanol
• Gut problems: GDV in dogs

  Expanded + twisted gut, opening between oesophagus-intestine closes
• Impacts of GDV in dogs

  • Animal try to belch or vomit
  • Blood flow interruption
  • Stomach rupture
• Gut problems: Bloated Rumen in cattle, caused

  1. Lush leguminous pastures

  2. High CHO diets = rapid fermentation

  3. More gas than rumen can handle

  4. No gas escape = gut blockage / impacation
• Gut problems: Bloated rumen in cattle, solution

  1. 200 ml veg oil / 100 ml paraffin oil

  2. Extreme cases: 10-20cm incision, vet needed to stitch + clean
• Gut protection: Feline Peritonitis (malfunctioning of abdominal cavity) cause

  Due to lapse in gut protection, ingestion of sharp objects, perforation of stomach, gall bladder + liver damage, spillage of gut contents
• Gut protection: feline infectious peritonitis

  • Enlarged mesenteric lymph node
  • Inflammation of intestine
  • Inflammation of abdominal wall
• Acidosis - ruminants

  • rumen ferment fibre (VFA) = pH>6VFA dissociate & absorb via rumen epithelium at pH>6
• pancreatitis in dogs

  inflammation of pancreas pancreatitis - enzymes are over activated within the pancreas causing digestion of itself mild = oedematoussevere = haemorrhagic
• Pancreatitis in dogs, what happens?

  Digestive enzymes spill into abdomen = secondary damage to liver, bile ducts & Small intestines
• Pancreatitis in dogs, cause:

  unknown, but eating rich, fatty meals
• Pancreatitis in dogs - symptoms -nausea-vomiting-diarrhoea-fever-abdominal pain-depression