Exam 3 - Equine Choke

Question 1

you have successfully resolved an esophageal obstruction that had been going on for 8 hours in a horse. on physical examination, you auscultate abnormal lung sounds particularly in the right ventral thorax. what can you conclude?

a. cardiac disease with pulmonary edema
b. diaphragmatic hernia
c. strangles
d. aspiration pneumonia

Answer 1

d. aspiration pneumonia

Question 2

a horse presents to you cough, and has feed material coming out of its nose. you suspect an esophageal obstruction. to confirm your diagnosis, you:

a. take a radiograph of the possible sites of obstruction ie. the cervical area, the thoracic inlet, & the caudal thorax
b. perform an ultrasound of the esophagus
c. perform a cytologic exam of the nasal discharge to confirm the presence of feed material
d. pass the nasogastric tube

Answer 2

d. pass the nasogastric tube

Question 3

what muscle type makes up the equine esophagus?

Answer 3

first 2/3: striated muscle
last 1/3: smooth muscle

Question 4

what is the most common esophageal disorder in horses?

Answer 4

choke

Question 5

what are the clinical signs of choke?

Answer 5

nasal discharge containing ingesta, coughing, retching, excessive salivation, extension of head/neck, sweating, & lethargy

Question 6

what materials commonly are implicated in causing choke?

Answer 6

beet pulp, hay cubes/pellets, carrots, apples, corn cobs

Question 7

where are the major locations where choke occurs?

Answer 7

proximal esophagus!!!!

midcervical, thoracic inlet, base of heart & cardia

Question 8

what are some differentials for choke?

Answer 8

dysphagia - neuro

pharyngeal obstruction - retropharyngeal abscess

reflux from the stomach - rare

Question 9

what initial diagnostic do you use in a choke case? why?

Answer 9

NG intubation - confirm obstruction & location

Question 10

if the horse has had multiple incidents of choke or is unresponsive, what diagnostics can you use?

Answer 10

endoscopy - FB, stricture, diverticulum

rads - plain & with contrast

ultrasound

Question 11

what is the treatment used for choke?

Answer 11

sedate them - xylazine or detomidine & lower their head

wait - if simple & acute, it may resolve on its own

no feed & water

lavage with water no oil

Question 12

if sedation & lavage are unsuccessful in treated choke, what should you do?

Answer 12

remove feed & water

place on antibiotics & NSAIDS & try again in a few hours

IVF to rehydrate & soften the impaction

refer if not resolved in 12 hours

Question 13

why should you refer a choke case earlier than 12 hours if it is located in the proximal esophagus?

Answer 13

the horse is at an increased risk of aspiration

Question 14

what treatment is used in refractory cases of choke?

Answer 14

more aggressive lavage - small tube through cuffed NG tube/equine esophageal lavage tube & biopsy forceps

general anesthesia

Question 15

T/F: most cases of choke resolve with one treatment of lavage

Answer 15

true

Question 16

what is the post-op needs of a choke patient?

Answer 16

feed slurry for 2 weeks

if ulceration - slurry until healed & recheck with endoscopy

Question 17

what are some common complications of choke?

Answer 17

aspiration pneumonia, ulceration, stricture, rupture, recurrence, & diverticulum

Question 18

why are antibiotics indicated in most cases of choke?

Answer 18

to prevent aspiration pneumonia

Question 19

what causes ulceration in choke?

Answer 19

pressure necrosis & trauma from prolonged NG tube intubation - important to monitor healing

Question 20

a horse with circumferential ulceration from choke has an increased risk of developing what?

Answer 20

esophageal stricture - long term diet modification & surgical correction if they get one

Question 21

what are the clinical signs of an esophageal stricture?

Answer 21

recurrent episodes of choke

Question 22

how are esophageal structures diagnosed?

Answer 22

history, endoscopy, & contrast rads

Question 23

what is the difference between these two endoscopic images of an esophagus?

Answer 23

bottom picture has circumferential ulceration - increased risk for esophageal strictures

Question 24

what does healing look like for esophageal strictures?

Answer 24

narrowest at 15-30 days

no significant increase in size after 60 days

don’t repair strictures until 60 days after initiating insult

Question 25

what is the treatment for esophageal strictures?

Answer 25

medical management - diet

surgical - incision & resection, esophageal tube through esophagotomy to create traction diverticula

Question 26

what causes an esophageal diverticulum?

Answer 26

dilation of the esophagus cranial to a stricture that occurs secondary to obstruction or trauma

Question 27

what are some clinical signs of an esophageal diverticulum?

Answer 27

recurrent choke

Question 28

how is an esophageal diverticulum diagnosed?

Answer 28

contrast rads, endoscopy, & ultrasound

Question 29

what is the treatment for esophageal diverticulum?

Answer 29

medical management or surgery

surgery - inversion of redundant mucosa or diverticulectomy

Question 30

what are some causes of esophageal rupture?

Answer 30

prolonged choke, kick, trauma from NG tube

Question 31

what are some clinical signs of esophageal rupture?

Answer 31

swelling, crepitation, pain, heat

Question 32

how is a ruptured esophagus diagnosed?

Answer 32

clinical signs, endoscopy, rads, & ultrasound

Question 33

what is the treatment for a ruptured esophagus?

Answer 33

open it to establish drainage & heal it as an open wound

place an esophagostomy tube either at the site of the rupture or proximal to it & leave it in place for a minimum of 10 days

Question 34

what is the prognosis like for an esophageal rupture?

Answer 34

depends on the location

if infection doesn’t migrate to the mediastinum - outcome is favorable

poor prognosis if feed material dissects down to the mediastinum