Gastrointestinal Disease of the Horse Part I Flashcards
what are the primary obstructions that cause choke?
foreign bodies
usually roughage
pelleted feed
what are the risk factors for choke?
prior esophageal trauma
poor dentition
wolfing or gulping food
when should you give antimicrobials in choke?
if risk for aspiration pneumonia is higher: longer duration or more proximal
what is buscopan?
anticholinergic spasmolytic agent (smooth muscle relaxant)
what is the breakdown of muscle in the esophagus?
cranial 2/3 is skeletal muscle
caudal 1/3 is smooth muscle
what can a double contrast esophageal study help with?
esophageal wall abnormalities or ulcerations
what are the sequela of esophageal choke?
esophageal erosions
esophageal rupture
aspiration pneumonia
esophageal stricture
esophageal diverticula
megaesophagus
how can recurrent choke be prevented?
routine dental management
feed management
why should you look at the mucous membranes and CRT of a horse with colic?
determine degree of cardiovascular collapse
what should you normally palpate in a rectal examination?
pelvis
bladder
uterus if female
inguinal rings
spleen
caudal left kidney
aorta
iliac arteries
ligament of cecum
how many bands does the cecum have?
4
palpate ventral band
where should you perform abdominocentesis?
right of midline at most dependent part of ventral abdomen
hand width caudal to xiphoid, hand width lateral to midline
what color should abdominocentesis be?
clear yellow
what should thee ratio of abdominal lactate to serum lactate be?
<2
what is anterior enteritis also called?
duodenitis/proximal jejunitis
how is metoclopramide a prokinetic?
enhances release of acetylcholine
what does erythromycin do?
works on motilin receptors
enhances gastric emptying in normal horses
what are the causes of secondary impactions?
intramural obstructions: tumors, strictures, diverticula, cysts
mediastinal masses: may cause extramural obstructions
what are the risk factors for choke?
prior esophageal trauma
poor dentition: main
wolfing or gulping of food
for what patients can you use cuffed naso-tracheal intubation?
smaller patients: limitations in length of ET tube
what can cause secondary impactions?
intramural obstructions
mediastinal masses may cause extramural
what is buscopan/butylscopolammonium?
anticholinergic spasmolytic agent: smooth muscle
what is oxytocin/peptide hypothalamic hormone?
smooth muscle relaxant at high doses
neuromodulator of centrally mediated proximal esophageal motility?
what are the effects of detomidinee/xylazine?
inhibitory effects on proximal esophageal motility in vivo
no effect skeletal muscle
pain/anxiety relief, decreased spontaneous swallows
how can you manage feed for prevention of recurrent choke?
avoid competition
use wet feeds in horses that do not chew well
feed smaller quantities frequently
ensure water access
complete feeds for horses with strictures
what should you look for in signalment and history?
age and breed
duration of signs
fecal output
observed degree of pain
prior administration of analgesia
which gastrointestinal organs can you palpate on rectal examination in which you can feel no bands?
small intestine
pelvic flexure: has one but not palpable
which gastrointestinal organs have 4 bands?
cecum: palpate ventral band
right ventral colon: cannot reach
left ventral colon
how many bands does the dorsal colon have?
left dorsal: 1
right dorsal: 3, cannot reach
what are the common abnormal findings in horses with colic?
abnormal amount free fluid
dilation of the stomach
visualization of left kidney
duodenum
other small intestine abnormalities
colon abnormalities
presence free thoracic fluid
what values in abdominocentesis are normal?
clear yellow
WBC <5,000/ul
total protein <2g/L
ratio of abdominal lactate to serum lactate <2
what are the clinical signs of anterior enteritis?
moderate to severe abdominal pain- gastric distension
moderate to severe gastric reflux
dehydration: tachycardia, prolonged CRT
may be associated with fever
how can you treat anterior enteritis?
gastric decompression- every 2 hours
NPO
antibiotics?
manage endotoxemia
motility stimulants
intravenous fluids
what are the effects of lidocaine?
may suppress primary afferent neurons
anti-inflammatory properties
direct stimulatory properties on smooth muscle
where might the primary sites of action for erythromycin be in horses?
cecum
large colon
how does neostigmine work?
increases receptor levels of acetylcholine by inhibiting enzyme acetylcholine esterase
what does bethanecol/acetylcholine receptor agonist do?
works throughout GI tract
improves gastric emptying
enhances cecal emptying
