Week 5- Conditions of the Equine Upper GI tract

Question 1

What is oesophageal obstruction/ choke?

Answer 1

hysical obstruction of the oesophagus, usually with organic matter
* Rapid ingestion of food
* Dry, coarse feed stuffs
* Poor mastication / Dental disease
* Primary oesophageal abnormalities

Question 2

What are the common areas where oesophageal obstruction occurs?

Answer 2

1. Proximal Oesophagus
2. Thoracic Inlet
3. Heart Base
4. Cardia

Question 3

What are the clinical signs of oesophageal obstruction?

Answer 3

• Profuse salivary/ food stained discharge
• Drooling
• Repeated spasm of neck muscles
• Anxiety/ Agitation
• Coughing
• Mild Tachycardia

Question 4

What intravenous sedation might you use for oesophageal obstrcution?

Answer 4

Alpha-2 agonist (e.g. detomidine/romifidine)
* + / - Butorphanol (opioid)

Question 5

What medication might you use for oesophageal relaxation?

Answer 5

• Buscopan
• Oxytocin

Question 6

How might you treat oesophageal obstruction without medication?

Answer 6

• Sedation
• Massage Oesophagus
• Pass a nasogastric tube
• Low volume lavage with the NG tube
• High volume lavage

Question 7

Name three long term complications of oesophageal obstruction

Answer 7

1. Stricture formation -> Circular fibrous submucosal scarring
2. Diverticulum formation -> Defects in the muscular layers of the oesophagus
3. Oesophageal rupture -> iatrogenic from the NG tube

Question 8

How can you help prevent oesophageal obstruction?

Answer 8

Dampen ‘high risk’ hard-feeds;
* Sugar Beet pulp
* Coarse chaff
* Feed smaller volumes more regularly
* Do not feed immediately after exercise (or after sedation!)
* Reduce excitement prior to feeding
* Allow access to hay prior to feeding hard-feed
* Place obstacles in the food bowl
* Large stones or plastic balls
* Pre-chopped, fine roughage for horses with dental disease
* Pre-soaked pelleted ration for horses with oesophageal disease

Question 9

What causes ESGD?

Answer 9

Due to direct contact with gastric acid
* Common along greater or lesser curvature dorsal to the
margo plicatus
* High prevalence in performance horses

Question 10

What are the risk factors for ESGD?

Answer 10

• High carbohydrate, low forage diet
• Intermittent feeding/ Periods of fasting
• Water restriction
• Stress
• Intense exercise

Question 11

What is EGGD?

Answer 11

Due to breakdown in mucosal defenses
* Inflammation - hyperaemia - erosion - ulceration
* In conjunction with squamous or as sole lesions
* High grade lesions and lesions associated with the pyloric
region are usually clinically significant
* Pyloric region more common

Question 12

What are the clinical signs of EGUS?

Answer 12

Poor performance
* Altered or variable appetite
* Preference for certain feeds
* Weight loss or poor weight gain
* Changes in behavior
* Coat changes – ill thrift
* “Girthing”/epigastric pain
* Recurrent colic

Question 13

What is a primary ESGD associated with?

Answer 13

Intensive management in animals with otherwise normal GIT’s

Question 14

What is secondary ESGD associated with?

Answer 14

Secondary to delayed Gastric Emptying resultant from other disease states

Question 15

How might you treat EGUS with Antacids/ Buffers

Answer 15

CaCO3- Mg(OH)2- Al(OH)3
Need to be given every 1
-3 hours to be effective
No clinical evidence to support use

Question 16

How would you use a mucousal protectant to treat EGUS?

Answer 16

Sucralfate
12-25mg/kg per os BID or TID
Binds to ulcer bed and stimulates
prostaglandin secretion
Benefit in early ulcer treatment

Question 17

How would you use a proton pump inhibitor to treat EGUS?

Answer 17

OMEPRAZOLE
Only licensed treatment available
Very effective, high safety margin
Irreversibly impair the
H+K+ATPase pump
Acid-labile
– requires enteric coating or buffering to
increase bioavailability

Question 18

What prostaglandin analogue would you use to treat EGUS?

Answer 18

Misoprostol
5 ug/kg PO BID or TID
Increased gastric mucosal blood flow,
supresses gastric acid
Not for ESGD / Not with Omeprazole

Question 19

What H2- Antagonist would you use to treat EGUS?

Answer 19

6.6mg/kg per os TID for 4-6 weeks
Inferior response cf Omperazole
May have more benefit in foals
Has been discontinued

Question 20

What do you need to consider when treating EGUS?

Answer 20

• Degree of acid suppression
• Persistence of effective supression after one dose, e.g frequency

Question 21

How can you help prevent/ manage EGUS?

Answer 21

Ensure continual grazing behaviour (18hrs per day!)
* Avoid prolonged fasting
* Provide regular access to pasture
* Feed smaller volumes more regularly
* Provide good quality forage
* Lucerne (legume roughage) high in Ca++ - natural buffering effect
* Avoid diets high in starch / soluble carbohydrates
* Utilise oil for weight gain if needed – corn oil shown to be beneficial
* Minimise stress
* Tailor exercise regimen – reduce periods of high intensity exercise
* Supplements – no evidence of efficacy, possible pectin-lecithin compounds