Choking and Gastric Disease

Question 1

You go to visit a horse in September which has suddenly developed hypersalivation. NAD on dental exam. You notice he also has some faecal staining on the hindquarters and frequently urinates. Whilst chatting to the owner about the horse’s history, you discover that he is fed on hay from a field which has a lot of red clover. What is your top differential?

Answer 1

Rhizoctonia leguminicola ingestion - fungus which grows on red clover

Question 2

Other than a mouth gag, what other equipment do you need to do a dental exam on a horse?

Answer 2

Head torch
Dental mirror
Dental pick
Rasps x3

Question 3

You are presented with a horse with hypersalivation. Which 2 broad differentials can you help rule in/out with focussed history questions?

Answer 3

Dietary issues
Dental issues

Question 4

You are investigating the cause of a horse’s hypersalivation. You have ruled out dietary and dental issues on history and dental examination, and are now going to look for obstructive abnormalities. List 3 possible differential diagnoses.

Answer 4

Retropharyngeal lymphadenopathy (strangles - Streptococci equi var equi)
Malformation/Injury/Oedema of pharynx/larynx/oesophagus
Laryngeal disorders - epiglottic cysts
Palate disorders - cleft palate, dorsal displacement of the soft palate
Guttural pouch disorders - tympany, empyema
Oesophageal obstructions and diverticula

Question 5

List 2 painful differential diagnoses for a horse with hypersalivation

Answer 5

Tooth - root abscess, broken, abnormal wear
Mandibule/Maxilla - fractures or trauma
Stomatitis/Glossitis
Temporohyoid osteoarthritis
Temporo-mandibular osteopathy

Question 6

What are the 4 broad causes of stomatitis/glossitis?
Stomatits = inflammation of oral mucosa
Glossitits = inflammation of the tongue

Answer 6

Foreign body - plant material or metal/wire
Ulcerative stomatitis - phenylbutazone toxicity or Blester beetle poisoning
Vesicular stomatitis - poxvirus and Rhabdovirus
Bacterial - Actinobacillus lignicresi

Question 7

Which bacteria is responsible for Wooden Tongue in horses?

Answer 7

Actinobacillus lignicresi

Question 8

You are called out to see a horse with ptyalism. The horse has been on box rest for a musculoskeletal injury obtained a week ago. On questioning, the owner tells you they have been giving the horse Bute. You do a dental exam and find ulcers on the tongue and oral mucosa. What is your top differential?

Answer 8

Phenylbutazone toxicity
Can also cause diarrhoea, anaemia, low white blood cell count, ulcers or haemorrhages in the gastrointestinal and oesophagus tract, and intestinal, kidney and liver diseases.

Question 9

You arrive at a yard to look at an 8 year old gelding. He presents with hypersalivation, ulcers and erosions of the mouth linings, shedding of the surface of the tongue and ulcers at the junctions of the lips. He also has slight inflammation and erosions at the coronary band of the hoof, and his owner mentions he’s been slightly lame for 2 days. What is your top differential diagnosis?

Answer 9

Vesicular stomatitis

Question 10

You have made a presumptive diagnosis of vesicular stomatitis on a horse with hypersalivation and ulcers at the junction of his lips, tongue and oral mucosa. What is your next step?

Answer 10

Ring the APHA as this is a reportable disease. Don’t leave until APHA vets arrive.

Question 11

What is temporomandibular osteoarthropathy?

Answer 11

Degenerative or inflammatory condition resulting in bony proliferation around the stylohyoid and temporal bone joint

Question 12

Give 3 clinical signs of temporomandibular osteoarthropathy

Answer 12

Acute onset vestibular dysfunction - head tilt, nystagmus, circling, strabismus
Head shyness
Facial paralysis
Corneal ulceration
Dysphagia
Difficult prehension
Complete/Partial unilateral hearing loss
Ptyalism

Question 13

A horse presents with a variety of clinical signs, one of which is hypersalivation. You have ruled out diet, dental, obstructive and painful conditions. What is your next step?

Answer 13

Complete neurological examination

Question 14

You are working as a vet in Texas. A horse you are examining presents with ptyalism and dysphagia. Which condition should always be on your differential list?

Answer 14

Rabies - take precautions

Question 15

Name 3 infectious causes of neurological disease in horses which could involve hypersalivation

Answer 15

Rabies - NOTIFIABLE
Viral encephalitis - NOTIFIABLE
Verminous encephalitis and Equine Protozoal Myeloencephalitis - not in UK
Meningitis
Botulism and Tetanus

Question 16

True or False?
CNS trauma, including cerebral damage/oedema and brainstem haemorrhage, can result in hypersalivation

Answer 16

True
Also CNS masses, e.g. cholesteroloma

Question 17

Lead poisoning can cause hypersalivation and other neurological signs, including impaired vision, ataxia, nystagmus and constipation, as well as colic, collapse and anaemia. What are 2 other toxic causes of hypersalivation and neurological signs?

Answer 17

Yellow star thistle - not in the UK
Hepatoencephalopathy - liver damage, e.g. due to pyrrolizidine alkaloid toxicity or Theiler’s disease (viral hepatitis)

Question 18

True or False?
Polyneuritis equi (immune mediated paralysis), Grass sickness (dysautonomia) and guttural pouch disease are all causes of hypersalivation along with neurological signs?

Answer 18

True
Also thyrohyoid osteoarthropathy and petrous temporal bone fracture/osteomyelitis

Question 19

Give 3 differential diagnoses for hypersalivation caused by muscular disease/dysfunction

Answer 19

Hyperkalaemia Periodic Paralysis (genetic mutation in sodium ion channels)
Nutritional Muscular Dystrophy (selenium or Vitamin E deficiency)
Polysaccharide Storage Myopathy (genetic mutation in glycogen storage)
Hypocalcaemia
Myotonia (delayed muscle relaxation)
Megaoesophagus

Question 20

A 3 year old mare presents with ptyalism, dysphagia, coughing, regurgitation and repeated head extensions and retching. What is your top differential diagnosis?

Answer 20

Oesophageal obstruction
Other clinical signs include distention of the left jugular furrow, crepitus, dehydration, pyrexia, etc.

Question 21

You diagnose a horse with an oesophageal rupture. You can hear crepitus in the neck on auscultation. What has happened?

Answer 21

Oesophageal rupture - crepitus from subcutaneous gas in the oesophagus

Question 22

What secondary disease can result from an oesophageal rupture?

Answer 22

Aspiration pneumonia

Question 23

What diagnostic tests could you do on a horse with a suspected oesophageal obstruction after physical exam?

Answer 23

Radiography - plain or contrast with barium paste +/- liquid barium with a cuffed NG tube
Oesophageal endoscopy
Gives additional information about possible ruptures and aspiration pneumonia

Question 24

How can you medically manage an oesophageal obstruction in the hopes that it will spontaneously resolve?

Answer 24

Remove all feed and water (including bedding)
IV fluids
NSAIDs
Sedation to relax the oesophagus
Oxytocin if obstruction is proximal

Question 25

You decide that an oesophageal obstruction in a horse won't resolve using IV fluids, sedation and NSAIDs. What other non-surgical options do you have?

Answer 25

Oesophageal lavage and drainage under sedation (ensure head remains below the thoracic inlet) Aggressive oesophageal lavage using a cuffed nasotracheal and naso-oesophageal tube - sedation or GA (double lumen NG tube allows you to put water in one side and pump out the other)

Question 26

What are the advantages of doing oesophageal lavage under general anaesthesia as opposed to standing sedation?

Answer 26

Minimises risk of aspiration Aids relaxation of the oesophagus

Question 27

After doing an oesophageal lavage to remove an obstruction, what should you do?

Answer 27

Repeat endoscopy to assess mucosal damage Small quantities of soft feed 48 hours post op Provide electrolytes and fresh water NSAIDs IV Broad spectrum antibiotics if there is systemic inflammation or abnormal thoracic exam/ultrasound

Question 28

How would you carry out a longitudinal oesophagostomy to resolve an oesophageal obstruction?

Answer 28

GA 10cm skin incision over the obstruction Retract the left carotid sheath Isolate oesophagus by packing with moist sponges 5cm incision into the oesophagus, distal to the lesion Place an oesophagostomy tube into the stomach and secure with a purse string suture Remove obstruction and close up IV fluids, broad spectrum antibiotics, NSAIDs Feed through the tube with slurry pellets for 7-10 days

Question 29

What is a common complication of doing a longitudinal oesophagostomy?

Answer 29

Laryngeal hemiplegia

Question 30

What are the complications of a oesophagostomy?

Answer 30

Aspiration pneumonia Oesophageal ulcer Oesophageal stricture Megaoesophagus Diverticula Oesophageal rupture

Question 31

What is an oesophageal diverticula?

Answer 31

Outpouching of the oesophagus

Question 32

What is the name of the divide between the glandular and non-glandular parts of the stomach?

Answer 32

Margo plicatus

Question 33

Name the 4 areas of the glandular stomach

Answer 33

Pylorus Antrum Ventral Glandular Fundus Cardia

Question 34

Name the 3 areas of the non-glandular stomach

Answer 34

Lesser curvature Greater curvature Dorsal squamous fundus

Question 35

What is the difference in function of the glandular and non-glandular areas of the stomach?

Answer 35

Non-glandular: storage of food Glandular: secretion of hydrochloric acid, pepsin, electrolytes and water

Question 36

Other than colic signs and weight loss, what are 4 more clinical signs of gastric disease?

Answer 36

Bucking/Rearing under the saddle Resentment of girthing and leg aid Poor performance Changes in temperament

Question 37

True or False? Clinical signs of gastric disease correlate with disease severity

Answer 37

False

Question 38

A client is worried about her horse getting gastric ulcers. What risk factors for gastric disease will you discuss with her?

Answer 38

Lack of access to forage Lack of access to water High carbohydrate diets High stress environments/individuals Other sources of pain (non-responsive cases)

Question 39

You have a horse booked in for a gastroscopy. How will you tell the owner to manage the horse in the 24 hours before the procedure?

Answer 39

Withhold food for at least 12 hours before Remove water around 4 hours before (possibly) Put a grazing muzzle on horses which eat bedding

Question 40

What sedation will you choose to sedate a 470kg horse for a gastroscopy?

Answer 40

Alpha-2 agonist and an opiate = detomidine and butorphanol Nose twitching is also a useful additional restraint for some horses - often only needed for the first 20 seconds as you pass through the nasal passages

Question 41

You arrive at a yard to do an endoscopy on a horse. How many people do you need to assist you, and what jobs will you give them?

Answer 41

One person to restrain the horse One person to pass the endoscope One person to control the endoscope

Question 42

How many minutes should you wait after sedation before passing the endoscope through for gastroscopy?

Answer 42

At least 5 minutes

Question 43

Which anatomical area should you try to avoid whilst passing the endoscope through the nasal passages?

Answer 43

The ethmoturbinates - damage causes epistaxis

Question 44

How can you locate the oesophagus on endoscopy?

Answer 44

Collapsible tube about 1cm above the arytenoid cartilages

Question 45

How can you tell the difference between glandular and non-glandular stomach on endoscopy?

Answer 45

Pale pink = squamous/non-glandular mucosa Dark pink = glandular mucosa

Question 46

You need to visualise all parts of the stomach when doing a gastroscopy. What can you do to enable this if the stomach contains food matter?

Answer 46

Jet water down the scope to lavage the stomach if needed

Question 47

Where is the most common place for glandular lesions?

Answer 47

Pyloric antrum

Question 48

How can you inflate the oesophagus when doing a gastroscopy?

Answer 48

Inflate it using pumped air

Question 49

Put the following levels of gastric squamous ulceration in order: - Large single or extensive superficial lesions - Intact mucosa with areas of hyperkeratosis - Small, single or multifocal lesions - Extensive lesions with areas of deep ulceration - Intact epithelium with no hyperkeratosis

Answer 49

0. Intact epithelium with no hyperkeratosis 1. Intact mucosa with areas of hyperkeratosis 2. Small, single or multifocal lesions 3. Large single or extensive superficial lesions 4. Extensive lesions with areas of deep ulceration

Question 50

What words/phrases might be used to describe lesions seen in glandular disease?

Answer 50

Mild/Moderate/Severe Focal/Multifocal/Diffuse Raised/Flat/Depresses Hyperaemic (engorged blood vessels) Haemorrhagic Fibrinosupprative

Question 51

You diagnose a horse with squamous ulceration of the stomach. What are your 2 first line treatment options?

Answer 51

Oral omeprazole (4mg/kg) Long acting, injectable omeprazole (4mg/kg once a week IM) +/- oral sucralfate 10-40mg/kg (mucosal barrier) if glandular disease also present

Question 52

A new grad vet at your practice has a horse with glandular disease in the stomach. What first line treatment will you advise?

Answer 52

Oral misoprostol (5mcg/kg - prostaglandin analogue) Long acting injectable omeprazole (4mg/kg once a week IM) +/- oral sucralfate (mucosal barrier) if squamous ulceration also present

Question 53

How long does it take for squamous ulcers to heal compared to glandular disease?

Answer 53

Squamous ulcers: within 3 weeks Glandular disease: about 3 months

Question 54

Why isn't there a licensed product to treat glandular disease in horses?

Answer 54

Not an ulcerative condition (according to lecture notes) so if there is only glandular disease then can use oral misoprostol, which is licensed for this in humans

Question 55

What 4 options do you have if your initial treatment for glandular disease doesn't seem to have cured it?

Answer 55

1. Continue on current therapy for another period of time or reduce interval between treatment 2. Long acting injectable omeprazole and oral misoprostol 3. Further diagnostics - transendoscopic mucosal biopsies 4. Switch to corticosteroids - dexamethasone or prednisolone if diffuse inflammation

Question 56

You have a client who has a horse with glandular disease. As well as treating with misoprostol, he has taken your advice to feed his horse ad lib roughage, reduce stress and eliminate carbohydrates from the horse's diet. He has now asked whether he should add feed supplements into the diet. What advice will you give?

Answer 56

Limited evidence for many feed supplements Buffers are of little use clinically Pectin and lecithin have some evidence of bolstering the mucous barrier - pectin is in sugar beet

Question 57

Would you ever look at long term medication for horses prone to glandular disease? If so, what?

Answer 57

Oral omeprazole is licensed for long term use at 1mg/kg orally once daily, but don't know how long term acid suppression affects the stomach Can target omeprazole use to high risk periods, but consider competition legally - prohibited by the BHA