Large Animal Sx Exam

Front 1

Normal (in horse):
HR
RR
Temp

Back 1

HR: 34-44
RR: 8-20
Temp: 99-101

Front 2

Non strangulating impaction.
Will you get reflux when you pass a NG tube?

Back 2

YES.

Front 3

Name the common sites of impaction (4)

Back 3

Base of cecum
R dorsal colon: enteroliths
Small colon: enterolith if small
PELVIC FLEXURE (most common site)

Front 4

Strangulating lesion
what is happening:
Proximal to lesion
At occluded area
Distal to lesion?

Back 4

Prox: distension
fluid & electrolyte loss.

Occlusion: peritonitis W/ possible perf, hemorrhage into lumen and wall of intestine, proliferation of bacteria in lumen, anoxic injury to epithelial cells (disrupted mucosal barrier, leakage of bacterial toxins, peritoneum may absorb the toxins --> endotoxemia).

Distal: dec fecal output

Front 5

________ carries the lipid A portion of LPS

Back 5

LPS binding protein

Front 6

What portion of the LPS is responsible for clinical signs of endotoxemia?

Back 6

Lipid A

Front 7

How does LPS binding protein work?

Back 7

Binds C14 cellular receptors on Monocytes. It combines with TLR-4 to stimulate the production of cytokines. Those mediators will cause: fever, hypotension, DIC, shock. The extrinsic pathway is also activated by exposure of TNFalpha on the monocyte or endothelium.

Front 8

Physiology of endotoxemia:
Initially:
Then:
which leads to:

Back 8

Initially: vasoconstriction (pale mm)

Then: pulmonary hypertension, arterial hypoxemia (membranes purple then pale).

Which leads to hypotension.

Front 9

Clinical signs of endotoxemia:
Early:
Late:

Back 9

Early: fever, leukopenia, hyperglycemia, ileus. increased HR and decreased gut sounds.

Late: Leukocytosis, hypoglycemia, coagulopathies.

Front 10

Reperfusion injury is a concern with strangulating lesions in the horse GI. What is this?

Back 10

When bloodflow is restored to the tissue, O2 comes with the fresh blood. Reactive Oxygen Metabolites are produced which cause tissue damage.
Neutrophils will come to the site and release their enzymes which destroy the tissue further.

Front 11

How do you treat a reperfusion injury

Back 11

Get to it before the neutrophils do. Give lidocaine CRI to decrease the neutro influx.

Flunixin will decrease the inflammation, too.

Front 12

Passing a nasogastric tube.
If you get a large vol:
If you get a small vol:
If you have relief after passing:
Also if you have no feces passed, where is the lesion?

Back 12

Large duodenitis/prox jejunitis, small intestine strangulation or obstruction.
Small: colonic lesions.
Relief: duodenitis/prox jejunitis.
No feces: cecal disease.

Front 13

Proximal Enteritis vs. SI strangulation

Back 13

PE: fever, leukocytosis, large vol reflux, less pain, lots of improvement after gastric decompression.

SI: amt of reflux dep on how long the lesion has been there. acute pain, hypoperfusion. Acidosis, distended loops upon rectal exam.

Front 14

Peritoneal Fluid.
(this is a very diagnostic test with colic!)
Normals
WBC count
____macros
____neutros
____ lymphos
____ eos
color:

Back 14

WBC 5-10,000
50% macros
40% neutros
10% lymphos
0% eos

Front 15

Impactions usually respond to medical tx. You definitely want to give analgesics and a laxative.
Common analgesics:
Common Laxatives:

Back 15

NSAIDS: Flunixin Meglamine: decr pain (blocks PG synthesis), improves CV status and binds LPS.
Alpha agonists: xylazine and detomadine
Opioids (usu give with alpha agonist): butorphanol
Laxatives:
Mineral oil (never give to a refluxing horse!)
Mg Sulfate: works by osmotic pressure. Don't give with DSS
Dioctyl Sodium Sulfosuccinate: will increase mucosal permeability and cause mucosal damage, though (works by irritating mucosa and causing it to secrete fluids to break up impaction)
Psyllum mucilloid : used w/ sand impactions.

Front 16

What laxative is usually used with a sand impaction?

Back 16

Psyllium Mucilloid

Front 17

Do you give oral fluids in a refluxing horse?

Back 17

NEVER!!
They are useful with impaction horses, though.

Front 18

Colic Surgery:
What approach do we use?

Back 18

Ventral midline celiotomy.
It allows for exteriorization of 75% of the GI tract.

Front 19

Name the parts of the large intestine and the number of bands each one has.

Back 19

Cecum: 4
Ventral Colon: 4
Left dorsal: 1
Right dorsal: 3
Small colon: 2

Front 20

What responsibilities lie within space systems structure?

Back 20

Space forces provide military leaders, operators and planners with enormous force enhancement products and services that are essential in achieving rapid dominance of the battle space. Today's space systems provide key information via global communications, navigation, weather, warning, and ISR to achieve full spectrum dominance across the range of military operations. In addition, space forces afford a commanding view of operations and provide an important military advantage.

Front 21

When removing an enterolith what parts of the intestine cannot be exteriorized?

Back 21

Transverse colon.
R dorsal colon.

Front 22

Best way to treat a large colon volvulus is...

Back 22

Coloplexy (adheres the ventral colon to the body wall to prevent it from happening again).

Front 23

Goal of treating large colon displacements.

Back 23

Restore natural anatomy.

Front 24

Where do you cut on the intestine when removing an enterolith?

Back 24

on the taenia (bands) on the antimesenteric surface of the intestine.

Front 25

Complication of removing an enterolith form the intestine.

Back 25

Adhesions. Use good sx technique and lavage the peritoneum to reduce the chance of this happening.

Front 26

List the Ddx for SI distention

Back 26

inguinal, epiploc hernia, obstruction/strangulation

Front 27

What can be a cause of luminal obstruction in a foal (4-24 mos old)?

Back 27

ascarids.
usually follows a dosing of anthelmintics.
can lead to intussusceptions or rupture.

Adult parasites can include: hemamelasmia ilei from a strongulus infection (larval migration)

Front 28

Old horse with colic and abdominal distention most likely has a

Back 28

strangulating lipoma

Front 29

Most common cause of a strangulating GI lesion in a horse 0-10 y/o is

Back 29

epiploic foramen. (4cm hole in the omental bursa. intestines like to get stuck here - usu the ileum and jejunum)

Front 30

List all causes of a strangulating colic in horses

Back 30

Lipomas
Epiploic foramen (0-10 y/o)
Volvulus
Inguinal hernia
Intussusception (jejunojenunal, ileocecal, ileoileal. less than 3 y/o usually)
Rent in mesentary
Adhesions
Rent in broad ligament
(and many others)

Front 31

Difference between indirect and direct scrotal hernias.

Back 31

§ Indirect- goes through vaginal ring into scrotum
• Small amount- short bowel segment
• adults
§ Direct hernias penetrate the subcutaneous space via the fascia and musculature next to the
vaginal ring
• occur in foals

Front 32

Causes of Intussusception

Back 32

• Ascarids, tapeworms
• Enteritis
• Mesenteric arteritis
• Dietary changes

Front 33

Responsible for ~ 74% of intussecption in horses

Back 33

Illeocecal intussecption