exam 3 - Small Intestine Flashcards
what is the MC sign of SI dz?
obstruction ===> pain and colic
pain in SI may occur d/t:
acute inflammation
simple obstruction
strangulating obstruction
what is a simple versus strangulating obstruction?
simple: obstructs flow w/in the lumen, NOT blood flow so NO devitalization occurs
strangulating: effected with loss of blood supply AND blocks the lumen
how common is neoplasia of the bowel?
UNCOMMON
signs of chronic inflammation or neoplasia?
poor performance
wt loss
recurrent episodes of colic
why does subcutaneous edema occur in many SI dzz?
protein losing enteropathy (PLE)
inflammation in bowel -> inc permeability -> leak albumin -> hypoalbuminemia -> loss of plasama oncotic pressure -> subQ edema if severe
t//f
SI dz does NOT usually cause diarrhea in adult horses
true
SI dz may cause diarrhea in foals - rotavirus enteritis and Lawsonia intracellularis
what pathogen may cause diarrhea in both foals and adult horses?
equine coronavirus
what is a great biomarker in the blood for tissue perfusion?
also is a good prognostic indicator.
lactate
high lactate => poor prognosis
diagnostic tests for SI dz?
- routine CBC, plasma biochemistry
- rectal palpation
- check for reflux
- u/s
- abdominocentesis
- etiological tests on feces
- laparoscopy
what are c/s of complete SI obstruction?
- severe pain, possibly refractory to analgesia
- high HR
- cardiovascular deterioration and endotoxemia
- reflux positive
- rectal palpation -> distended loops of small intestine
dx of complete SI obstruction?
- u/s evidence
- abdominocentesis: serosanguineous peritoneal fluid
what is the best method to detect SI distension?
u/s
hyperemia of gums and a toxic line along the tooth/gum interface suggests what illness?
endotoxemia - SIRS - cardiovascular compromise
dry digesta in the large intestine suggests what?
an obstruction in the SI
if SI obstruction is suspected, what is the FIRST STEP for initiating immediate Tx?
pass stomach tube - check for reflux
note: must create a siphon to help get the tube going
what does a serosanguineous tap suggest?
devitalized intestine
iatrogenic
t/f
SI obstruction is considered an emergency and often warrants referral to hospital
true
what treatments are instituted immediately for SI colic?
- analgesia
- decompress stomach - NG intubation
- fluid therapy
what is a common cause of acute inflammation that leads to SI obstruction?
proximal enteritis
what are 2 common causes of simple obstruction that leads to SI obstruction?
ileal impaction
ascarid impaction
what are 2 common causes of strangulating obstruction (StO)
lipoma anatomical excursions (mis adventures)
what is proximal enteritis?
- acute inflammation
- edema
- hemorrhage
- necrosis
what are common names for proximal enteritis?
duodenitis / proximal jejunitis
“anterior enteritis”
what does inflammation of a segment of the intestine lead to?
- dysperistalsis: paralytic ileus, functional obstruction
- inc fluid secretion, dec fluid absorption
proximal enteritis often effects what types of horses?
well managed horses - dz of luxury
higher grain diet
confined
etiologic agent of proximal enteritis?
unknown
maybe:
Clostridium perfringens / difficile
salmonella
c/s of proximal enteritis:
colic
lots of reflux
lethargy
fever s/t
CBC - inflammation, hemoconcentration
PBP: azotemia, elevated lactate, hyperproteinemia
classic presentation for what dz:
animal painful w colic, you place stomach tube, drain stomach so pain goes away then animal becomes profoundly depressed / lethargic
proximal enteritis
CBC and PBP in proximal enteritis?
CBC: inflammation and hemoconcentration
PBP: azotemia, elevated lactate, hyperproteinemia
dx of prox enteritis?
- compressible loops of SI on palpation
- thickened loops of SI on U/s
- yellow / orange peritoneal fluid
t/f
protein levels in peritoneal fluid suggests prognosis of animal
true
higher protein => poorer prognosis
prox enteritis vs Strangulation:
bowel loop distension
loops of distended SI are less tight in PE
what does a bloody reflux duriing prox enteritis suggest?
assoc w less favorable outcome
inc risk of laminitis
prox enteritis vs Strangulation:
blood work?
CBC inflammatory in PE
stress changes in StO
prox enteritis vs Strangulation:
after draining, what c/s about animal’s attitude is most noteworthy ?
lethargy MOST noteworthy in PE
prox enteritis vs Strangulation:
quantity of refulx?
higher quantity - substantial - during PE
prox enteritis vs Strangulation:
peritoneal fluids
yellow orange in PE
also fluid protein is high w normal TNCC
serosanguineous in StO
often elevated protein and TNCC
prox enteritis vs Strangulation:
GGT levels
GGT elevated in StO
prox enteritis vs Strangulation:
response to medical tx?
PE responds well to medical Tx typically
w/o Sx, StO condition will deteriorate
PE tx:
gastric decompression - stomach tube*** hold NPO fluids anti endotoxemia tx abx [controversial] prokinetic drugs celiotomy
prognosis of PE?
survival = 66-87%
68% developed gastric ulcers w/in 24 hours
risk aspiration pneumonia and phlebitis
risk of laminitis high: 7.5-28.4% and higher if reflux is bloody
where does ileal impaction commonly occur?
at the ileum - where the ileum joins the LgI
MC geographic loc of ileal impaction?
SE USA
what type of obstruction occurs in ileal impaction?
simple luminal obstruction
1* ileal impaction occurs d/t:
coarse ingesta - poor quality forage
2* ileal impaction occurs d/t:
ileocecal jxn dysfxn
ileal hypertrophy
damage / occlusion by tapeworms
what type of tapeworms often cause ileal impaction in horses?
anoplocephala perfoliata
older animals may acquire ileal impaction 2* to what idiopathic muscular condition?
idiopathic thickening of muscularis layer of the ileum ==> dec luminal diameter at the end orad to the ileocecal junction
c/s of ileal impaction?
moderate pain - tachycardia, diminished borborygmi
later stages:
positive reflux
SI distension
rectal palpation of ileal impaction?
early = doughy to solid tubular mass extending proximad from ileocecal jxn
later = extensive SI distension
early case of ileal impaction Tx:
- hold NPO
- analgesia
- drain stomach
- laxative [mineral oil or DSS]
- fluid therapy
late case of ileal impaction Tx:
surgical reduction
jejunocecostomy
px of ileal impaction?
deworm for tapeworms - praziquantel
do not feed course roughage
MC ascarid to cause impaction in equine?
parascaris equorum
t/f
parascaris equorum is ubiquitous in the horse environment
true
route of infection of ascarids and life cycle / pathogenesis?
fecal oral transmission
all young exposed
parasite larvae migrate out of gut and into liver -> milk spots on liver -> migrate to lungs -> respiratory signs -> couging and discarge -> re swallow -> adults enter SI
t/f
equine often develop a self cure from ascarid infection
true
develop natural immunity
ascarid parasitism issues MC seen in what age animals?
young foals
why should foals with a high ascarid load NOT be given high doses of de worming agents?
be cautious during what age range
worms become stunned and die -> form physical foreign body obstruction -> often occurs near duodenum and jejunum
foals 3-12 mos old
c/s of ascarid impaction:
colic signs after de worming severe SI obstruction abdominal distension positive reflux may see worms in reflux and/or feces
dx ascarid impaction?
circumstances, c/s
PE
u/s
how to manage an incomplete ascarid impaction:
relieve pain
decompress stomach
laxative
fluids
how to manage a complete obstruction?
decompression surgery
resection / anastomosis surgery
how to px ascarid impaction:
use benzimidazole de wormers
worms are resistant to macrocyclic lactones [ivermectin] and pyrimidine derivatives
what 2 intestinal issues may complicate ascarid impaction patients?
jejunal intussusception or perforation
what is SI strangulation?
obstruction accompanied and complicated by loss of blood supply to affected segment
Tx of SI strangulation:
SURGERY
resection and anastomosis
remove strangulated segment
remove part of pre stenotic segment
prognosis of SI strangulation?
guarded
post op ileus likely, peritonitis and adhesions, anastomotic site dysfunction
in SI strangulation, why is the pre stenotic segment removed?
b/c it is damaged d/t distension
what does high lactate in the peritoneal fluid suggest?
intestinal de vitalization
t/f
lactate conc in peritoneal fluid may be elevated to a greater extent than that of the blood
true
some types of SI strangulation?
pedunculated mesenteric lipoma
herniation
volvulus
intussusception
in SI strangulation d/t hernia, what 2 locations commonly herinate?
epiploic foramen
gastro splenic lig
MC strangulation type in MO?
pedunculated mesenteric lipoma
common presentation of horse with mesenteric lipoma:
mature or older horse - often over 15 yo
obesity is a risk factor
MC cause of critical SI colic in MO *****
how do mesenteric lipomas cause colic?
what region of intestines?
as a result of their mass impingement on the intestinal lumen [mild]
MC SI but can affect descending colon
dx of mesenteric lipoma?
at surgery
how do hernias cause colic?
section of intestine is obstructed after moving through an aperture => strangulation is a common sequela
what is the anatomy of the epiploic foramen?
a slit, 4-6 cm wide
dorsal: Cd love of liver, Cd vena cava
ventral: R lobe of pancreas, gastro splenic fold, hepatic portal vein
risk factors of epiploic foramen entrapment?
thoroughbred breed
winter months
cribbing and wind sucking - d/t altered / abnormal abdominal pressures
what configuration of epiploic forament entrapment is most common?
Left to Right
c/s of epiploic foramen entrapment?
- abdominal pain
- SI obstruction [MC jejunum and ileum, rare colon]
- rectal palpation findings equivocal in early stages
- reflux - later stages
- abnormal peritoneal fluid
dx epiploic foramen entrapment?
u/s obstructed SI - R Cr abdomen
what type of hernia should be considered especially when a stallion presents with colic?
inguinal hernia
how to check for inguinal hernia during PE?
palpate scrotum
rectal palpation
u/s
what age is commonly found to have inguinal hernias?
common management?
neonates
reducible scrotal swelling
managed by repeated manual reduction - wait for tissue to becomes stronger as animal grows/develops
obstruction and strangulation are still a risk
what is volvulus?
twisting of intestine about its mesenteric axis?
a volvulus of the root of the mesentery can affect ___ % of the SI
80%
what age group MC gets volvulus?
foals and young adults
1* volvulus:
consequence of abnormal motility - dysperistalsis
2* volvulus:
abnormal motility consequent to entrapment or other obstruction [herniated jejunum, for example]
what region MC for volvulus in equine?
SI
c/s volvulus?
severe SI obstruction and strangulation
tx volvulus?
resection and anastomosis
jejunocecostomy
prognosis of volvulus?
only 58% survival - high inter operative attrition
80% survival if survives anesthesisa
48% post operative complication rate
partial obstruction d/t intussusception typically presents as :
chronic recurrent colic
dec feces and appetite fever wt loss post prandial colic failure to thrive
risk factors for intussusception:
MC in foals and horses less than 3 yo
enteritis [dysmotility]
parasites
abrupt diet change
prior anastomosis
presence of focal mass along intestinal wall [granuloma, neoplasia]
what is the pathognomonic sign on u/s for intussusception?
target sign
what is ileo cecal intussusception?
ileum into cecum thru ileocecal jxn
intussusceptum = ileum intussuscipiens = cecum
clinical presentation of ileo cecal intussusception?
risk factor?
young horse, intermittent colic responds to Tx
risk: Anoplocephala perfoliata parasitism
what is Meckel’s diverticulum?
remnant of primitive yolk sac
incomplete atrophy of the embryonic vitellointestinal duct
where is Meckel’s diverticulum loc?
loc at anti mesenteric border
distal jejunum
ileum
may be connected to umbilicus via mesenteric band
what issues arise at Meckel’s diverticulum?
- bacT overgrowth -> risk of acute intestinal inflammation
- distends w ingesta: painful -> necrosis and possible rupture
- facilitates volvulus and intussusception
- can loop around and strangulate adjacent gut like pedunculated lipoma
SI adhesions predispose animal to what issues?
obstruction
herniatioin
volvulus
what is the nature of chronic infiltrative SI dz?
chronic inflammation
granulomatous enteritis
lymphocytic plasmacytic enteritis
eosinophilic enteritis
what kind of neoplasia my manifest as chronic infiltrative SI dz?
alimentary LSA
clin presentation of chronic infiltration dz?
wt loss and ill thrift
hypoalbuminemia / ventral subQ edema
recurrent colic
Dx of chronic infiltration dz?
Tx?
Prognosis?
oral glucose absorption study
biopsy
tx - corticosteroid?
prog - unfavorable
what is etiologic agent of proliferative enteropathy (EPE)?
proliferative ileitis
Lawsonia intracellularis infection
MC presentation and sings of EPE?
young horse MC than mature horse
hemorrhagic diarrhea and colic => hypoalbuminemia
dx EPE?
Tx?
dx: PCR of feces, Aby titer
Tx: abx
erythromycin
chloramphenicol
tetracycline
