Dysphagia in the Horse

Question 1

What is dysphagia? How is it further defined in the horse?

Answer 1

Difficulty (or inability) to swallow
In the horse its further defined as any problem associated with eating

Question 2

How does dysphagia manifest in the horse?

Answer 2

Ptyalism (Quidding - dropping of food) and/or nasal regurgitation

Question 3

Can horses vomit? Why or why not?

Answer 3

No - high muscular tone and close proximity of both gastric sphincters

Question 4

What are the 3 pathophysiological mechanisms by which dysphagia can be defined?

Answer 4

Abnormalities in prehension, mastication, swallowing

Question 5

What are the abnormalities occurring in these 3 photos?

Answer 5

Top left - evidence of dropped pieces of partially chewed feed on the ground (quidding)
- Could be indication that horse is not able to masticate properly
Bottom left - foal with milk coming out of both nostrils (dysphagia)
- Unable to swallow properly
Right - Horse with food/saliva coming out of both nostrils (dysphagia)
- Not able to swallow properly, possibly due to esophageal obstruction

Question 6

What is the primary organ system involved in dysphagia?

Answer 6

GIT

Question 7

What are the secondary organ systems that could be involved in dysphagia?

Answer 7

neurological, neuromuscular, muscular and/or metabolic problems that may affect prehension, mastication or swallowing (cranial deficits, neuromuscular disorders, hypocalcemia, etc)

Question 8

How do you define the location of dysphagia in the horse? 3 options

Answer 8

Prepharyngeal
Pharyngeal
Postpharyngeal

Question 9

What is prepharyngeal dysphagia? How does this differ to pharyngeal dysphagia?

Answer 9

Localizes problem rostral to pharynx
- Usually see ptyalism and dropping of food
(QUIDDING)
- Includes disorders of prehension and mastication
- Nasal regurgitation of food and coughing is NOT a feature (pharyngeal dysphagia)

Question 10

What is pharyngeal dysphagia?

Answer 10

NASAL REGURGITATION MAIN SIGN
- Localizes problem to either oropharynx/nasopharynx
- In addition to ptyalism, see nasal regurgitation of food, water and saliva +/- coughing
- Concern for aspiration pneumonia - food accumulates in nasopharynx due to inability to swallow and only way out is through the nose, if it cannot come out of nose it will go into lungs

Question 11

What is postpharyngeal dysphagia? Which type of dysphagia is this most similar to?

Answer 11

Localizes problem to esophagus
Clinical signs similar to those for pharyngeal
dysphagia (ptyalism, nasal regurgitation of food, water and saliva +/- coughing) and potential for aspiration pneumonia

Question 12

What are common lesions associated with prepharyngeal dysphagia in the horse?

Answer 12

Dental fractures/tooth issues most common
Periodontal disease
Diastema
Oral foreign body/ass
Mandibular/Maxillary fractures
Botulism (flaccid paralysis, dropping food)
Neuromuscular issues

Question 13

What are common lesions associated with pharyngeal/postpharyngeal dysphagia in the horse?

Answer 13

Guttural pouch disease (mycosis, empyema)
Cleft palate (foals)
Esophageal obstruction
Grass sickness
Botulism

Question 14

What is grass sickness?

Answer 14

Toxic damage to nervous system (cause unknown) which affects GIT function (nervous system issue)
Leads to esophageal paralysis and regurgitation of food
Associated with grazing

Question 15

Lay out the diagnostic approach for treating a horse with dysphagia

Answer 15

• History, Physical Examination, Oral Examination
• Observation → Watch horse eat/drink and note
  timing of problem (prehension, mastication or
  swallowing)
• Neurological examination
• Passage of NG tube
• Endoscopy, Ultrasonography
• Radiography +/- contrast