equine gastrointestinal anatomy and physiology Flashcards
discuss the approach to the horse with colic
- hx
- physical exam
- diagnostic techniques (rectal palp, nasogastric intubation, abdo paracentesis)
what are the problems of a grazing diet
- grass contains silicates (harder than enamel and resulta in rapid wear of teeth
- cellulose and hemicellulose in diet cannot be digested and requires breakdown by bacteria
how much tooth erupts per year in a normal horse
2-3 mm per yer
what are the complications of high concentrate diets in horses
- changes chewing movement
- changes rate of wear
- leads to overgrowths
how much saliva is produced by the horse per day
10-12 litres
what is the importance of saliva in the horse
- lubricates food (preventing choke)
- buffer stomach acidity (bicarb)
what causes choke
- dry food
- food that is improperly chewed
- unsuitable types of food (whole apples, potatoes, grooming brushes)
relate how the different compartments of the equine GIT contain different volumes to function
- stoomach carries relatively small amount of volume as less digestive importance occurs here (only chemical and mechanical mixing/breakdown)
- large intestine large because more digestion occurs here
name the 2 sphincters of the equine stomach
- cardiac sphincter
- pyloric sphincter
what are the functions of the equine stomach
- secrete hydrochloric acid, pepsinogen and mucus (in glandular)
- mix food with enzymes
discuss digestion in the small intestine
carbohydrates: Starch -> glucose and galactose
protein: oligopeptides -> di/tripeptides and amino acids
fat: triglycerides -> fatty acids and monoglycerides
what is not digested by the small intestine in the horse
fructans and cellulose (digested in LI by bacteria)
list common diseases of the equine small intestine
- parasites
- diarrhea
- impactions
- twists and strangulations
- malabsorption
what are the functions of the equine large intestine
- microbial digestion
- water absorption
what are the purposes of taenial bands and sacculations
- sacculations increase surface area
- taenial bands are muscular bands important in mixing and movement of ingesta
what are the functions of teh caecum and large colon
- microbial digestion and water/electrolyte absorption
list the flexures of the equine large intestine, their locations and issues associated if any
- sternal flexure = ventral aspect, cranial abdomin
- pelvic flexure = caudal abdomen, narrows, makes 180 degree turn and has to go vertically up, fod gets stuck
- diaphragmatic flexure = dorsal cranial abdo
what is the function of the small colon
- storage of feces and absorption of remaining water
on per rectum palpation of the horse, what will you feel in the left hemisphere
- spleen (against body wall, smooth with sharp border and no palpable masses)
- caudal pole of left kidney (smooth margins and against spleen)
- pevlic flexure ( varies in diameter, no sacculations, no taenial bands palpable, indentable contents, can move across to midline)
- small colon ( small diameter, 2 taenial bands, fecal balls)
what will you feel per rectum in a horse on the right hemisphere
caecum = large diamter, gas/fluid/feed filled, sacculations, caudal and medial taenial band running dorsal to ventral
causes of colic
- diet
- anatomical predisposition
- motility disturbances
- infections
- parasites
- ulcertion
- other organs/systems (false colic)
what should be assessed on clinical exam of a horse with suspected colic
- overall impression
- demeanour
- degree of pain
- any self trauma
- abdominal distension
- posture
- TPR
- pulse and mucus membranes (quality of pulse, digital pulse, CRT, colour)
- gastrointestinal sounds
- skin turgor (hydration status)
list firther diagnistic tests for colic
- rectal exam
- nasogastric intubation (esp for acute colic if fluid builds in stomach and cant pass through)
- abdominal paracentestis
- ultrasound
- blood sample
- fecal exam
- endoscopy
- radiographs
why is nasogastric intubation indicated for some cases of colic
- horses cant vomit -> if fluid reflux builds in stomach can rupture - needs to be removed
- releives choke
- gastric impaction
- administer oral fluids/treatment
why is peritoneal tap useful in colic
- provides important infor for critical cases
- can be useful in chronic colic
- analyze colour, volume, turbidity, total protein, cell number and type
