Esophageal Obstruction in the Horse Flashcards
What is the common name for esophageal obstruction in the horse?
Choke
Which food is the most common cause of obstruction in the UK?
Sugar beet
Which horses are more at risk of esophageal obstruction?
Bold eaters
Old horses with poor dentition
Is esophageal obstruction an emergency? What should treatment be aimed at?
Yes - its an emergency
Treatment should be directed primarily at relieving the obstruction and preventing complications
What is the prognosis of esophageal obstruction?
Good
What is the anatomy of the horse esophagus?
120cm in length
Upper 2/3 striated muscle, lower 1/3 smooth muscle
Innervated by peripheral nervous system (vagus nerve)
What is important to consider when choosing drugs to target the esophagus?
Muscle type
What are the risk factors associated with esophageal obstruction in the horse?
Poor dentition
Bolt feeders
Type of feed
Horses with previous history of choke
Sedation, General Anesthesia
Exhaustion
Dehydration
What are the clinical signs of esophageal obstruction?
Anxiety
Ptyalism (hypersalivation)
Attempts to swallow
Bilateral nasal regurgitation of food
Intermittent neck extension and retching
Pain
Respiratory distress +/- coughing
Palpable swelling on left side of neck
Abnormalities in what levels will occur with longstanding choke?
Dehydration/Electrolyte abnormalities
What should you NEVER do with NG tube?
Force it against resistance
How do you diagnose esophageal obstruction in the horse?
History, Physical examination
Passage of NG tube (never force)
Observation of clinical signs (ptyalism, bilateral nasal regurgitation)
Endoscopy
Radiography +/- contrast
What is the treatment for esophageal obstruction in the horse?
Sedation - Xylazine, Detomidine, Romifidine
Buscopan “hyoscine butylbromide” - antispasmodic
Remove food and water
How long should you treat a horse with esophageal obstruction before deciding to refer?
Do not treat for longer than 12 hrs prior to considering different approach
What is this?
What is esophageal lavage? How is it properly performed?
Use sedation - detomidine, romifidine
Ensure head is below point of the shoulder (to prevent regurgitation)
Pass NG tube and lavage obstruction with WARM WATER while GENTLY advancing tube
How are most obstructions freed up?
Most obstructions are made of food and will be broken up by warm water
What should you NEVER USE to lavage the esophagus? Why?
Mineral oil - fatal if aspirated
How is endoscopy properly performed?
2-3 m endoscope
Used to visualize obstruction
Direct pressurized flushing
Can also attempt removal of material with biopsy instrument
Bore small hole through obstruction
What is the dietary aftercare for a patient recovering after esophageal obstruction? What should you not feed and why?
Restrict food for 12-72 hrs to promote healing of esophageal mucosa
Gradually re-feed over 48-72 hrs with low bulk minimally abrasive diet
NO HAY - too abrasive!
What is typical aftercare after esophageal obstruction?
Restrict food, take time reintroducing non-abrasive feed
Broad spectrum abx (TMPS/Doxy)
NSAIDs - pain/inflammation control
How is endoscopy useful as a tool in aftercare for a patient recovering from esophageal obstruction?
Endoscopy can be useful to assess degree of mucosal damage and to monitor for strictures
What increases the risk of developing stricture? When are strictures more likely to occur after esophageal obstruction?
If damage is circumferential there is high risk for developing stricture - Affects prognosis and MUST be considered if obstruction has been there for a while!
What is a stricture?
When tissue heals it shrinks down (scarring) which reduces lumen size of esophagus and increases risk of blockage/obstruction occurring again
What are the after-complications associated with esophageal obstruction?
Aspiration pneumonia
Ulceration
Stricture
Diverticula
Perforation
In how esophageal obstruction cases is apiration pneumonia also seen?
67%
How do perforations most often occur with esophageal obstruction?
Usually iatrogenic (stomach tube)
Prevention measures for esophageal obstruction?
Perform thorough dental exams often (especially in older horses)
ID horses that bolt food - use slow feeders/double hay nets
Ensure dry pelleted feeds are moistened
Consider complete pelleted feed for horses with recurrent choke
