chocking horse

Question 1

what are the clinical signs and additional clinical signs of a chocking horse?

Answer 1

Clinical presentation
* Regurgitation food, water & saliva
◦ Bilateral frothy nasal discharge containing water and saliva.
* Ptyalism
* Dysphagia
* Coughing
* Repeated head extensions or retching
◦ Gagging and retching may be noted, particularly in proximal esophageal obstructions.
* Anxiety

Other clinical signs:
* Distention - left jugular furrow (right side some horses)
* Crepitus (esophageal rupture)
* Ptyalism

Clinical signs of complications
◦ Dehydration
◦ RR/abnormal pattern
◦ Fever
◦ Other

Question 2

how can endoscopy be used to ivestigate the chocking horse?

Answer 2

• Sedation
  ◦ Xylazine - 0.2 - 0.5 mg/kg IV
  ◦ Detomidine - 0.03 - 0.06 mg/kg IV
  ◦ Topical lidocaine 4 - 6 ml in nasal and pharyngeal mucosa
• Minimum of 200 cm to view length of esophagus
• Irrigation and insufflation
  ◦ mucosal defects
  ◦ changes in lumen size
• Pass, view while withdrawing
• Normal - pale pink to white-gray and longitudial folds

Question 3

how can radiology be used to investigate the chocking horse?

Answer 3

• Survey plain films
• Contrast Radiography
  ◦ Barium (Iodinated contrast for rupture)
  ‣ Barium paste PO
  ‣ Liquid barium by cuffed NG tube
• Double contrast
  ◦ Liquid barium by cuffed NG tube under pressure
  ◦ Gives best definition
• Additional information
  ◦ Rupture
  ◦ Aspiration pneumonia

Question 4

what are the priciples for spontaneous resolution of choke in horses?

Answer 4

• Remove all feed and water
• IV fluids
• NSAIDS/Analgesics
• Sedation - Relaxation of the oesophagus
  ◦ Xylazine - 0.05 – 1.1 mg/kg IV
  ◦ Detomidine - 0.03 – 0.06 mg/kg IV
  ◦ Butorphanol – 0.01 – 0.02mg/kg IV in combination with Xylazine or Detomidine
  ◦ Acepromazine – 0.01 – 0.05 mg/kg IV or IM
• Oxytocin 0.11 – 0.22 IU/kg IV (for proximal obstruction)

Question 5

what are the principles behind assisted resolution of choke in horses?

Answer 5

• Esophageal lavage and drainage
  ◦ Sedation – detomidine
  ◦ Maintain head below the thoracic inlet
  ◦ Repeated attempts at 8–12h intervals with supportive care
• Aggressive esophageal lavage
  ◦ Cuffed nasotracheal and nasoesophageal tube
  ◦ Decreases likelihood of aspiration
  ◦ Greater mechanical advantage
  ◦ Standing or under general anesthesia
• General anesthesia
  ◦ Minimizes aspiration
  ◦ Aids relaxation

Question 6

once choke is relieved what are the principles of management and to prevent reobstruction?

Answer 6

• Repeat endoscopy to assess mucosal damage
• Fusiform dilation predisposes to re-obstruction
• Small quantities soft feed 48 hours post relief
• Provide electrolytes and fresh water
• Anti-inflammatories
• Broad spectrum antibiotics

Question 7

what are the principles behind an esophagostomy in horses?

Answer 7

Longitudinal Esophagotomy with primary closure or second intension healing
* Standing with tube in place
* Approach dictated by location of lesion
* Laryngeal hemiplegia common complication

• Incision 5-cm, distal to lesion
  ◦ Mucosal sutures
• Indwelling tube
  ◦ Into stomach
  ◦ Purse string
• Pelleted slurry