Equine Respiratory Surgery

Question 1

What are 4 differentials for a horse with epistaxis?

Answer 1

Ethmoid hematoma
Guttural pouch mycosis
Ventral straight muscle rupture
Trauma/fracture

Question 2

What are 3 differentials for a horse with nasal discharge?

Answer 2

Primary sinusitis
Tooth root abscess (secondary sinusitis)
Guttural pouch empyema

Question 3

T/F: Horses cannot hemorrhage fatally from guttural pouch mycosis

Answer 3

False; roughly 50% that hemorrhage do so fatally

Question 4

What are the four spaces of the equine head we are concerned with in respiratory Sx?

Answer 4

Oral cavity
Nasal cavity
Paranasal sinuses
guttural pouches

Question 5

What are the four meatuses and which one do we want the NG tube to go into?

Answer 5

Dorsal (Can hit ethmoid and cause hemorrhage)
Ventral (NG)
Common
Middle

Question 6

What are the six paranasal sinuses and which one connects directly to the nasal cavity?

Answer 6

Maxillary (connects to nasal cavity)
Frontal
Shpenopalaine
Dorsal, middle, and ventral conchal sinuses

Question 7

T/F: Tooth issues can sometimes present as sinus issues

Answer 7

True

Question 8

What are the three mains signs associated with sinus problems?

Answer 8

Facial swelling
Nasal discharge
Abnormal percussion of the sinus

Question 9

What are the best diagnostics to aid in determining the best course of action when sinus dz present?

Answer 9

Radiography

Endoscopy

Question 10

How does fluid in the sinuses appear on radiographs?

Answer 10

Increased opacity

Fluid line

Question 11

Where does one see drainage in the middle nasal meatus?

Answer 11

Nasomaxillary Aperture

Question 12

What are the five most common surgical diseases of the sinuses?

Answer 12

Sinusitis
Ethmoid hematoma
Sinus cyst
Fractures
Neoplasia

Question 13

What is the most common disease of the sinus causing discharge, what are the two types, and how are they treated?

Answer 13

Sinusitis
Primary infection - Irrigation and systemic abx
Tooth root abscess - Tooth removal and flushing

Question 14

T/F: Ethmoid hematomas often metastasize

Answer 14

False; they are benign but locally invasive

Question 15

How are ethmoid hematomas treated?

Answer 15

Trans-endoscopic intralesional formalin injections

Surgical removal via bone flap

Question 16

T/F: Sinus cysts are not visible radiographically

Answer 16

False

Question 17

T/F: Sinus cysts removed surgically often results in a poor outcome

Answer 17

False; outcome is usually good with surgical intervention

Question 18

T/F: Neoplastic lesions are often extensive at time of diagnosis and have poor prognosis

Answer 18

True

Question 19

What are the six most important anatomical landmarks of the guttural pouch?

Answer 19

Stylohyoid bone
External carotid artery
Internal carotid artery
Maxillary artery
Ventral straight muscles
Mucosal fold containing glossopharyngeal and hypoglossal nerves

Question 20

What are five surgical diseases of the guttural pouch?

Answer 20

Tympany
Empyema
Mycosis
Temporohyoid osteoarthropathy
Rupture of the ventral straight muscles

Question 21

What is guttural pouch tympany and how is it treated?

Answer 21

Developmental failure of GP depression resulting in elastic, non-painful swelling of the parotid region; may be unilateral or bilateral
Unilateral - establish an opening in the septum between the tympanic and normal GP
Bilateral - establish openings through the flap in the pharyngeal wall

Question 22

How does guttural pouch empyema develop and what are three associated signs?

Answer 22

Young horses develop it secondary to URT infections (Strangles)
Intermittent to continuous nasal discharge
Parotid swelling and pain
+/- Dyspnea

Question 23

What is a chondroid?

Answer 23

Mass of inspissated pus in the guttural pouch

Question 24

How are chondroids treated?

Answer 24

NSAIDS
Lavage with physiologic solution
Systemic abx if indicated by culture/sensitivity
Sx to remove inspissated pus and chondroids

Question 25

What are the four surgical approaches to the guttural pouch?

Answer 25

Hyovertebrotomy Viborg's triangle Whitehouse approach Modified Whitehouse

Question 26

What is the most common sign of guttural pouch mycosis?

Answer 26

Epistaxis

Question 27

What are signs related to CN IX-XII damage in regards to guttural pouch mycosis?

Answer 27

Horner's syndrome Dysphagia Dyspnea

Question 28

T/F: Cranial nerve damage associated with guttural pouch mycosis tends to resolve

Answer 28

False; it is permanent

Question 29

What are five treatment options for guttural pouch mycosis?

Answer 29

NSAIDs to reduce inflammation (usually too slow) Blood transfusions and IV for shock Nutritional support for dysphagia Vascular occlusion to mitigate bleed risk Sx **Vitamin E/Selenium given for nerve damage**

Question 30

Which three arteries may be a source of guttural pouch bleed?

Answer 30

Internal carotid External carotid Maxillary

Question 31

How should guttural pouch vasculature be occluded?

Answer 31

NOT ligation (circles of Willis) Balloon catheter Transarterial coil embolization

Question 32

How does temporohyoid osteoarthropathy arise? What cranial nerves does it affect?

Answer 32

Secondary to inner/middle ear infection, associated with fusion of the temporohyoid joint CN VII and VIII

Question 33

How is temporohyoid osteoarthropathy treated?

Answer 33

NSAIDS Styloid ostectomy Ceratohyoidectomy

Question 34

What is seen on endoscopy with ventral straight muscle rupture?

Answer 34

Collapse of pharynx Blood clot Arteries intact No diphtheritic membrane

Question 35

How do horses generally rupture the ventral straight muscles?

Answer 35

Falling over backwards

Question 36

How is ventral straight muscle rupture treated?

Answer 36

``` Stall rest for 30d Elevated feed and water Broad-spectrum abx NSAIDS Follow-up exams ```