Lecture 2: Esophageal Obstruction and Equine Gastric Ulcer Syndrome Flashcards
what is the most common cause of choke/esophageal obstruction
Inadequately soaked beet pulp
Describe the anatomy of the esophagus
2 muscle layers:
1. Muscularis mucosa: in cranial esophagus, becomes more substantial as it approaches cardia- composed of smooth muscle, longitudinal orientation
- Muscularis externa: present along entire length of esophagus. Composed of striated muscle in midthoracic region and smooth muscle in caudal 1/3
What are the 4 most common sites for choke
- Cervical esophagus
- Thoracic inlet
- Base of heart
- Cardia/terminal esophagus
What are the sedation options for treatment of choke and what do they do
- Xylazine: alpha 2 agonist with sedative and pain relieving properties ~10 minutes
- Butorphanol- partial kappa/sigma agonist opioid with pain relieving properties. Stops coughing and gagging (antitussive)
- Acepromazine: muscle relaxant and anti-anxiety, no pain relief
What muscle relaxants are used to tx choke and what do they do
- Buscopan/N-butylscopolammonium: anti-cholinergic, antispasmatic, smooth muscle relaxant
- Acepromazine
What is a side effect of Buscopan/ N-butylscopolammonium
Tachycardia! Important to check heart rate prior to use because can cause V-fib
What is a common NSAID used to tx choke
Banamine
What antibiotic is commonly used for choke
Excede- broad spectrum antibiotic- not administered orally
What mucosal protectant is commonly used to tx choke
Sucralfate
When passing an NG what two things should you do to prevent aspiration pneumonia
- Nastrotracheal tube with cuff
- Heavy sedation with head down
Once NG is passed what do you want to give
6-8 liters of water and electrolytes
T of F: you can feed a horse right after tx choke
F: hold off feed for 12 hours and slowly reintroduce wet, soft feed
What do you do if you are unsuccessful in relieving the choke
- Supportive care: night of IV fluids and muscle relaxants
- Refer to scope
- GA
What are some common life threatening complications of choke and which is the most common
- Aspiration pneumonia- most common
- Acid base and electrolyte abnormalities
- Dehydration
- Esophageal mucosal irritation
What is the MOST common life threatening complication of choke
Aspiration pneumonia
What are some less common life threatening complications of choke
- Stricture formation
- Esophageal perforation
- Pleuritis
- Laminitis
- Laryngeal paralysis
- Horners syndrome
What are some ways to prevent choke
- Dental care
- Slow feeders
- Elevated feeders
What are some signs of gastric ulcers
Poor appetite, dullness, attitude change, decreased performance, reluctance to train, poor body condition, mild colic, salivation when tacking, poor hair coat, weight loss, sour disposition, avoidining hard feed, prefer hay, bruxism, cribbing
What is wrong here
Multifiocal, diffuse, gastric ulcers near the pylorus. Grade 3-4
What is the pathophysiology of ESGD
Increased exposure of squamous mucosa to acid
What is the pathophysiology of EGGD
Breakdown of normal defense mechanisms that protect the mucosa from acidic gastric contents
What are some predispositions to ESGD
Racehorses, increase intensity and duration of exercise, high fiber, >6 hours between meals, feeding grain at 1% body weight
What are some predispositions to EGGD
Warmbloods, exercised more than 5 days a week, stress
Access to pasture may be protective in what gastric ulcer syndrome
EGGD
What is the only antemortem diagnostic for ulcers
Gastroscopy
What grade ulcer is this? What are the characteristics of this grade?
grade 4: extensive ulcers, often merge to give areas of deep ulceration, raw
What grade ulcer is this? What are the characteristics of this grade?
grade 0: stomach lining intact, no reddening
What grade ulcer is this? What are the characteristics of this grade?
Grade 2: stomach has small single or multiple ulcers
What grade ulcer is this? What are characteristics of this grade
Grade 1: stomach lining intact, but there are some areas of reddening
What grade ulcer is this? What are the characteristics of this grade
Grade 3: Stomach has large single or multiple ulcers
What is the key for ESGD treatment
Acid suppression, pH >4 for 16-18 hours daily
What are the main drugs used to treat ESGD
Proton pump inhibitors
1. Omeprazole
2. H2 antagonists
What is the dose for omeprazole and how long is duration of tx
1-4mg/kg for 21 days
Should omeprazole be given on full or empty stomach
Empty to improve absoprtion
Followed by food 30 minutes later
What is the main H2 antagonist used to tx ESGD
Ranitidine
What is the dose for ranitidine
6.6mg/kg PO q8
What are some nutritional management strategies for ESGD
Avoid high starch grain, frequent feeding every 4-6 hours or free choice, vegetable oil
How do we grade EGGD
Anatomic location, description (hyperemia, hemorrhagic, pseudomembranous), and size (% effected area)
What are the drugs used to tx EGGD
- Sucralfate
- Misoprostal
- Omeprazole
What is dose for Sucralfate in EGGD
20mg/kg PO q12 for 8 weeks
How many hours after omeprazole can you administer sucralfate
2 hours
What is the mechanism of action of sucralfate
Adheres to ulcerated mucosa, stimulates mucose secretion, prostaglandin E synthesis and enhanced blood flow
What is the dose for Misoprostal
3-5 ug/lg PO q12
What is the mechanism of action of Misoprostal
- Inhibits basal and nocturnal gastric acid secretion by stimulating prostaglandin E1 receptors on parietal cells
- Induces mucus and bicarbonate secretion, increase mucosal blood flow and epithelial repair
What is the dose for omeprazole in tx EGGD
4-8mg/lg PO q12-24hrs for 8 weeks
T of F: can use omeprazole as monotherapy in EGGD
False!
Can you give Misoprostal with omeprazole
No because antacids decrease absoprtion
What are some ways we can prevent gastric ulcers
- Provide minimum of 2 rest days/week
- Turn out when possible
- Feed prior to exercise so no empty stomach while at speed
