Guttural Pouch Disease

Question 1

What is a GP?

Answer 1

Diverticula of Eustachian tube

Question 2

What species have GP?

Answer 2

Horses

Question 3

How much fluid can a GP hold?

Answer 3

300-500mls

Question 4

GP communicates with what other structure and through what orifice?

Answer 4

Pharynx, pharyngeal orifice

Question 5

What are the divisions of the GP? Which is the largest division?

Answer 5

Later and medial pouches, medial pouch is larger

Question 6

What vascular structures are in the GP?

Answer 6

Internal carotid
External carotid
Maxillary artery

Question 7

What neural structures are in the GP?

Answer 7

Sympathetic trunk

CN - VI, IX, X, XI, XII

Question 8

GP tympany is seen in what age group?

Answer 8

Foals

Question 9

What is GP tympany?

Answer 9

Non-painful distention of the GP with air

Question 10

Is GP tympany unilateral or bilateral?

Answer 10

Can be either

Question 11

What is most noticeable clinical sign of GP tympany? What other CS can you see?

Answer 11

Soft, non-painful external swelling of the throat-latch region in a foal.
Other - respiratory stertor, resp difficulty, dysphagia (+/- asp pneumonia)

Question 12

Cause of GP tympany?

Answer 12

Unknown, thought to be congenital. Possible abnormal or excessive mucosal flap at pharyngeal orifice acting as a one way valve.

Question 13

Diagnosis of GP tympany?

Answer 13

Signalment, clinical signs, air-filled GP on rads

Question 14

Treatment of GP tympany?

Answer 14

Surgery usually necessary. If unilateral - fenestartion between the two GPs. If bilateral - resection or modification of pharyngeal orifice.

Question 15

Prognosis of GP tympany (complicated and uncomplicated)?

Answer 15

Good if uncomplicated

Poor to guarded if dysphagia or asp pneumonia

Question 16

What is GP empyema?

Answer 16

Purulent exudate in the GP

Question 17

What organisms can cause GP empyema?

Answer 17

Strep equi or zooepidemicus

Question 18

What causes GP empyema?

Answer 18

Usually secondary to a URI

Can be cause by rupture of a local lymph node

Question 19

Clinical signs of GP empyema

Answer 19

Nasal discharge
Regional LN enlargement
Dysphagia (less common)

Question 20

Chronic GP empyema can cause a firm mass called what?

Answer 20

Chondroid

Question 21

Diagnosis of GP empyema

Answer 21

History of URI
Physical exam
CS
Confirmed with endoscopy and rads

Question 22

Treatment of GP empyema

Answer 22

Aggressive lavage
Local and systemic abx
Surgical lavage and drainage my be needed if severe (chondroids present)

Question 23

Prognosis of GP empyema?

Answer 23

Good to excellent

Question 24

What is GP mycosis

Answer 24

Development of fungal plaques in the GP

Question 25

Where in the GP do fungal plaques form?

Answer 25

Dorsal aspect of the GP

Question 26

Common pathogen in GP mycosis?

Answer 26

Aspergillosis

Question 27

Why do epistaxis and dysphagia occur with GP mycosis?

Answer 27

Erosion of arteries/nerves by the fungal plaque

Question 28

Clinical signs of GP mycosis

Answer 28

Hemorrhage/epistaxis if an artery is involved - can be fatal

Dysphagia, horners, facial nerve paralysis if neural structures involved

Question 29

Diagnosis of GP mycosis

Answer 29

Clinical signs

Endoscopy

Question 30

When would you not continue with endoscopy if you suspect GP mycosis?

Answer 30

If a hemorrhage or blood clot is present at the pharyngeal orifice. This could result in disruption of the clot and more hemorrhage.

Question 31

Treatment of GP mycosis

Answer 31

Can resolve spontaneously.
If epistaxis or dysphagia observed, you should intervene.
Surgical occlusion of affected arteries, even if only neuro signs are present.
You can give antifungals, just less efficacious.

Question 32

Prognosis of GP mycosis

Answer 32

Guarded to fair.

Dysphagia worsens prognosis, takes time for neural structures to heal.