L01: Equine Gastro 1 Pt.1 (Sanchez) Flashcards
esophageal obstruction aka
Choke
causes of choke
hay, pellets, or cubes
beet pulp
FB
rapid consumption w/o adequate chewing
where do most esophageal obstructions occur?
proximal esophagus (less commonly: thoracic inlet)
CS of choke
distress head extension salivation nasal d/c of food/saliva** (complication = aspiration pneumonia) lethargy dehydration \+/- abn lung sounds
Dx of choke
Hx/CS
external palpation
resistance upon passage of nasogastric tube
endoscopy/rads
drugs used in tx of choke for sedation
xylazine
detomidine
butorphanol
help prevent aspiration pneumonia
resolution of choke
sedation**
gentle passage of stomach tube
esophageal relaxation with buscopan/oxytocin/lidocaine (caution: oxytocin can cause constriction)
management of choke
- Analgesia: NSAIDs
- slow return to normal diet
- exclusion of underlying causes (dental exam, endoscopy)
- tx/prevent. of pneumonia (abx)
complications of choke
- damage to recurrent laryngeal n. –> roaring
- linear esophageal erosions
- circular erosions
- ruptured esophagus
basic mechs. of GI pain*
distension of a viscus
traction on the mesentery
ischemia
inflammation
how to determine small vs. large intestine colic?
rectal exam, U/S
how to determine strangulating vs. non-strangulating?
pain, U/S, abdominocentesis
1 reason for surgical referral
pain that is non-responsive to meds
most common types of colic**
large intestinal non-strangulating:
- Gas/spasmodic
- large colon impaction
what percent of colic resolve in field w/o tx?
80-85%
CS of subtle colic
anorexia
lying down more than usual
dec. fecal prod.
CS of moderate colic
pawing
stretching
flank watching
abd. distention
“Kidney Colic”
horse stretches out and urinates frequently (not necessarily problem of KID)
CS of severe colic
rolling
thrashing
becoming cast
facial abrasions
chars. of pain
duration
persistence
severity
response to analgesics
breed and individual variability (ie. Tennessee Walkers stoic, foals drama queens)
severe pain replaced by depression: major concern
take temp before or after rectal exam?*
BEFORE
HR 80-100 indicative of:
very painful horse
check mm for:
color
moisture
CRT (reflection of hydration status/perfusion)
toxic line (indicative of strangulating lesion)
where check horse’s perfusion?
mm, extremities
Borborygmi
gut sounds
-complete absence of sounds is clinically relevant
basic questions that may be answered by rectal palpation
distention (yes/no)?
if distended, is it SI or LI?
gas, fluid, or feed causing distention?
masses?
when to use nasogastric intubation
for EVERY moderate to severely painful colic
- can be life-saving
- > 2-3L net reflux is significant
- > 5L –> consider leaving tube in place
relevance of lactate in colic workup
can indicate hydration status or hypoxemia or indicate anaerobic process happening in the body
What gives measures of hydration status/lactate?
PCV/TP/Blood gas
FLASH exam
transabd. U/S in 7 key spots to give you view of all the important things
- looks at gastric distention, kidneys/spleen, free abd. fluid, etc.
types of imaging used for colic
- transabd. U/S
- Rads
- Endoscopy
use of abdominocentesis in colic
used to differentiate between SI strangulating and non-strangulating
-shouldn’t be performed if results won’t influence the course of tx
interpretation of abdominocentesis in colic
interpret. based on gross appearance and odor: -strangulating usually serosanguinous fluid (red)
- rupture usually indicated by feed material in liquid (could also indicate accidental enterocentesis)
- compare lactate to plasma: >2x plasma indicates strangulation
- N fluid does NOT rule out strangulation!
clicker Q: which of the following would be most indicative of severe pain?
rolling repeatedly
inital colic therapy
analgesic therapy (gastric decompression, drugs) fluid therapy
analgesics/sedatives used for colic
NSAIDs
a2-agonists
opioids
buscopan
maintenance fluid dose
40-50 ml/kg/day
management of dehydration for colic considerations
maintenance fluids hydration status deficits metabolic status electrolyte abnormalities enteral or IV fluids *need less fluids when not eating*
fluid therapy options
Enteral
-excellent option unless >2-3L reflux
IV fluids
-use if lot of reflux, severe pain, substantial dehydration
Laxatives (ie. Psyllium for sand, Mineral oil, MgSO4)
mineral oil good marker of GI transit only but doesn’t have much therapeutic use
Equine Gastric Ulcer Syndrome (EGUS) CS
mild colic after eating, not eating grain, not eating as vigorously, behavioral changes
Dx of EGUS
- CS, response to tx
- gastroscopy (view squamous vs. glandular)
most common site for ulceration
squamous mucosa along lesser curvature
T/F: should hold horse off feed at least 12 hr. before scoping for ulcers
T
Risk factors for EGUS
diet exercise environment NSAIDs Foals
Antacids act on:
lumen to prevent HCl release
Sucralfate acts on:
M-B Barrier to prevent pepsin and H+ release
PPI acts on
gastric gland
H2-antagonists acts on
gastrin, Ach, H2 binding to parietal cell where H+ is pumped out
omeprazole
(GastroGard)
- oral proton pump inhibitor
- preventative therapy for ulcer formation
- more effective than H2 antagonists for horses kept in work
Gastroduodenal Ulcer disease (GDUD)
- usually in foals stricture)
- CS: colic, poor appetite, etc.
Prognosis of GDUD
- fair to good with sx
- reasonable with medical tx if no outflow obstruction
- expensive and labor-intensive tx
most common kind of stomach cancer
squamous cell carcinoma
ways to determine if GDUD has outflow obstruction
rads +/- contrast
U/S
gastroscopy
Causes of Non-strangulating colic (SI and LI)
1) intraluminal obstruction (gastric/ileal/cecal/large ascending colon/small colon impaction)
2) large colon displacement
3) gas/spasmodic colic
T/F: gastric impaction is rare
T
ileal impaction risk factors
SE US
Coastal Bermuda hay (esp. with new bale)**
tapeworms
CS of ileal impaction
- mod. to severe pain
- distended SI on rectal exam
- initially no reflux
- peritoneal fluid: usually normal, TS N or high, lactate similar to plasma
2 most common small intestinal non-strangulating colics
1) ileal
2) proximal enteritis
Tx of ileal impaction
- gastric decompression
- withdrawal of feed/water
- analgesics, IV fluid tx
- Sx if not improving or abn peritoneal fluid
- de-worm for tapes
- good/excellent prognosis
Cecal impaction risk factors
- broodmare near parturition
- recent general anesthesia
freq. of cecal impaction
rare; occurs spontaneously
CS of cecal impaction
- variable pain
- no net reflux
- N peritoneal fluid (usually)
- cecal distension with feed or fluid on rectal exam**
Tx of cecal impaction
- withdraw feed
- enteral laxatives
- IV fluids
- sx often needed
- guarded prog.; rupture common
Common causes of large colon impaction
feed or sand
most common site of large colon impaction
pelvic flexure
-2nd most common cause of colic
Risk factors for large colon impaction
- inadequate water intake
- sand ingestion
- parasites
- poor dentition
- sudden stall confinement
- alternate source of pain (ie. eye)
- coarse roughage
CS of large colon impaction
- mild/mod. pain
- dec./absent fecal output
- dec. borborygmi
- impaction/variable gas distention on rectal exam
- variable reflux
- normal ab tap
Tx of large colon impaction
- withdraw feed
- manage pain
- enteral fluids
- IV fluids if reflux
- very good prognosis
CS of small colon impaction
colic, abd. distention, low volume diarrhea
dx of small colon impaction
via rectal exam
tx of small colon impaction
usually medical
frequency/prognosis of small colon impaction
rare freq., good prog.
enterolith
calculi within the intestine (Mg ammonium phosphate (struvite))
Enterolith risk factors
- Arabians
- High protein diet
- high colonic luminal pH
CS of enterolith
- intermittent mild/mod. pain
- rectal exam often normal
- may NOT see in rads!
- peritoneal fluid usually N
Tx of enteroliths
sx!
restrict alfalfa
decrease pH?
type(s) of extraluminal non-strangulating obstruction(s)
Large Colon displacement (Left or Right dorsal)
Retroflexion
Spasmodic (gas) colic
T/F: large colon displacement difficult to differentiate from other non-strangulating LC obstructions
T
direction of large colon displacement
left or right dorsal
prognosis/frequency of large colon displacement
prognosis: good with medical or surgical therapy
frequency: relatively common
types of non-strangulating intraluminal obstructions
ileal impaction cecal impaction large colon impaction small colon impaction enteroliths
types of strangulating obstructions
small intestinal lesions
large intestinal volvulus
left dorsal large colon displacement aka
nephrosplenic entrapment
dx of left dorsal displacement
Rectal exam: distended colon lat. to KID +/- ventrally displaced spleen
U/S: gas-filled colon prevents imaging of L kid; ventral displacement of SP
tx of left dorsal displacement
- phenylephrine (to shrink spleen)/excercise
- rolling under gen. anesthesia
- sx correction
