Equine GIT Flashcards
What is different in the equine stomach compared to other species?
- 2 distinct regions of mucosa
- Squamous and glandular epithelium
- Separated by margo plicatus
- 5-15 litre capacity
Describe the equine small intestine
- 10-30m long
- 3 parts (duodenum, jejunum, ileum)
- Loosely coiled
- Long mesenteric attachment, no fixed position
List some of the common diseases of the small intestine in the horse
- Parasitic infestation
- Diarrhoea
- Impactions
- Twists and strangulation
- Infiltrative bowel disease (malabsorption)
Describe the equine large intestine
- Adaptation to high roughage diet
- Microbial digestion and water absorption
- Made up of caecum, large colon, small colon
- Ventral colon and caecum have taenia and haustra
What is the function of the taenial bands?
- Muscular bands
- Important in mixing and moving ingesta
What is the function of the sacculations/haustra?
Increase surface area
Describe the equine caecum
- Blind ending sac
- 2 muscular valves controlling entry and exit of ingesta
- 25-35litre capacity
- Major site for microbial digestion of cellulose, absorption of water and electrolytes
- Pacemaker for motility
Describe the equine large colon
- 4 regions: RVC, LVC, LDC, RDC
- Capacity for 55-130 litres
- Major site for microbial digestion of cellulose, absorption of water and electrolytes
Describe the equine small colon
- Storage of faeces and absorption of remaining water
- Narrow diameter
What is the clinical importance of the equine large colon?
- Narrow diamter, common site for impactions
- Esp. miniature horses
Describe the diet and feeding habits of the horse
- Grazing diet
- Need high fibre
- Trickle feeders - graze continuously for up to 17 hours a day
- Not designed to eat lush grass or cereals
What is the fate of cellulose and hemicellulose in the horse?
- Cannot be digested
- Breakdown by bacteria
What is the fate of carbohydrate, protein and fat in the diet?
- Digested and absorbed in small intestine
- Starch to glucose and galactose
- Oligopeptides to dipeptides, tripeptides and AAs
- TAGs to fatty acids and monoglycerides
What is the fate of fructans in the diet?
- Not digested in SI or stomach
- Pass into LI
- Digested by bacteria
- Produces acidic environment
- Alters LI bacterial flora
- Can lead to pathological disease
Where does water absorption take place in the horse?
- Caecum
- Large colon
Describe what can be felt in a rectal palpation
- Start top middle (12 oclock) move anticlockwise
- Aorta at top
- Then caecum on RHS (sacculations, taenia, large diameter, can feel body)
- Then small colon (small diameter, 2 taenial bands, faecal balls)
- Pelvic flexure (variable diameter, no sacculations, no taenial bands, indentable contents, can move avross midline)
- Caudal edge of spleen (against body wall, smooth, sharp border, no palpable masses)
- Nephrosplenic ligament (between spleen and left kidney)
- Caudal pole of left kidey (smooth margins, against spleen)
What are the classes of cause for abdominal disease?
- Diet
- Anatomical predisposition
- Motility disturbances
- Infection
- Parasites
- Ulceration
- Other organs/systems (false colic)
(DAMIPOU)
What does colic refer to?
Abdominal pain
Give examples of how diet can cause colic
- Rapid change in diet, microflora take time to adapt
- Increased gas production = predisposed to colic
Give an example of an anatomical predisposition that may lead to colic
Inguinal hernia in a foal
Give an example of a motility disturbance that may cause colic
Box rest
What should you look out for on physical examination of a horse presenting with colic?
- Overall impression of horse
- TPR
- Mucuous membranes
- Pulse quality, CRT, digital pulses
- Gastrointestinal sounds
- Abdominal distension
- Skin turgor (not always accurate for hydration status)
What diagnostic tests may be carried out in a horse presenting with colic?
- Blood sample
- Nasogastric intubation
- Faecal examination
- Abdominal paracentesis
- Ultrasonography
- Endoscopy
- Radiography
- Rectal palpation
