Week 1 - URT Surgery in Small Animals

Question 1

What does BOAS stand for?

Answer 1

Brachycephalic obstructing airway disease

Question 2

What are primary causes of BOAS?

Answer 2

Primary = born with

Stenotic external nares
Relative overlength of the soft palate
Relative oversize of the tongue
Tracheal hypoplasia/stenosis
Sliding hiatal hernia

Question 3

What are secondary causes of BOAS?

Answer 3

Secondary = consequence of airway obstruction

Hypertrophy of the soft palate
Tonsillar hypertrophy
Everted laryngeal ventricles/saccules
Laryngeal collapse
Pharyngeal collapse
Glosso-epiglottic mucosa displacement
Scrolling of epiglottic cartilage
Vomiting/regurgitation

Question 4

Is there a grading system for BOAS?

Answer 4

Yes

Owners want vet to be aware of this and provide advice on breeding. The lower the score, the better!

Question 5

What is tracheal hypoplasia?

Answer 5

Narrowing of the trachea

Primary cause of BOAS

Animals can present with no clinical signs.

Question 6

What is the medical management for BOAS?

Answer 6

Weight loss
Reduction of exposure to heat, short regular exercise rather than long walks and over-excitement
Harness rather than collar

Question 7

What are the surgical options for BOAS?

Answer 7

Nasal wedge-resection
Alar fold resection for stenotic nares
Partial staphylectomy of the soft palate
Folded-flap palatoplasty
Tonsillectomy (normally done alongside above options)

Question 8

How does laryngeal collapse occur?

Answer 8

When there is an obstruction in the airway, the diaphragm and intercostal muscles have to work harder and generate a larger inter-thoracic negative pressure.

This affects the structure in which air passes through and if the structures are flexible, then they can collapse.

Question 9

Is laryngeal collapse staged?

Answer 9

Yes - there are three different stages

1 = laryngeal sauce eversion

2 = medial deviation of the cuneiform cartilage and aryepiglottic fold or aryepiglottic collapse

3 = medial deviation of the cuneiform cartilage and aryepiglottic fold or aryepiglottic collapse

Question 10

How can laryngeal collapses be managed?

Answer 10

Surgically - excision of everted laryngeal saccules

Question 11

What is this problem and how can it be fixed?

Answer 11

Primary BOAS = external nasal aperture stenosis

Surgical management
- Rhinoplasty (wedge-resection)
- Alar fold resection

Question 12

What are the surgical options to correct the soft palate?

Answer 12

Partial staphylectomy

Folded-flap palatoplasty

Question 13

What is the normal movement of the arytenoid cartilage on inspiration and expiration?

Answer 13

Inspiration – cartilages are abducted

Expiration – cartilages are adducted (air break)

Expiration at exercise – cartilages are abducted

Question 14

What is laryngeal paralysis and what causes it?

Answer 14

The nerves and muscles that control the movements of one or both arytenoid cartilages of the larynx cease to function, and instead of opening during aspiration and closing during swallowing, the arytenoids remain stationary in a somewhat neutral position.

Question 15

What are the clinical signs of laryngeal paralysis?

Answer 15

Stridor
Cough
Dyspnoea
Change in phonation (bark)
Exercise intolerance
Collapse

Signs worse with severity and when dog is hot, excited or exercised.

Question 16

How do you diagnose laryngeal paralysis?

Answer 16

Characteristic clinical signs
Auscultation of the larynx and the thorax
Laryngoscopy (under a light plane of general anaesthesia)
Straight-bladed laryngoscope (Miller)

Question 17

Wha should you also check when dealingg with laryngeal paralysis?

Answer 17

Survey inflated radiographs of the thorax
Neurological examination
Routine haematology and blood biochemistries
Thyroid function testing?

Animals are often older when present so should look for concurrent disease as well:
- Cardiac
- Lower respiratory tract
- Dysphagia
- Megaoesophagus
- Hypothyroidism

Question 18

What is emergency medical management can be done in laryngeal paralysis?

Answer 18

Rest (calm – both dog and owner)
Supplemental oxygen
Cooling
Sedation
Intravenous access
Intravenous corticosteroids (?)

Last resort:
Anaesthetise => tracheostomy tube placement (?)

Question 19

What is the surgical option for laryngeal paralysis?

Answer 19

Arytenoid lateralisation (tieback)

Aims to widen the rima glottdis and prevent dynamic collapse of the arytenoid cartilage

Performed as unilateral procedure

(dogs present bilateral, cats present unilateral)

Question 20

What are the post-op requirements after surgery to fix laryngeal paralysis?

Answer 20

Observe feeding and drinking (aspiration risk)
Strict rest for 2-3 weeks
Antibiotics
Analgesics
Harness

Question 21

What complications could there be after surgery to fix laryngeal paralysis?

Answer 21

Seroma formation
Aspiration pneumonia
Inadequate lateralisation
Suture failure/recurrence
Change in bark
In the right hands, surgical outcome is general very good

Owner will me most aware of change in bark -> worn them!

Question 22

What is tracheal collapse and which breed is most disposed to it?

Answer 22

A condition of excessive collapsibility of the trachea which usually results in dorsoventral flattening of the tracheal lumen (trachea becomes flat)

Yorkshire terrier

Question 23

What are the clinical signs of tracheal collapse?

Answer 23

Classic ‘goose-honk’ cough
Pulling on collar & lead
Exercise
Anything that makes the dog cough

Question 24

Are tracheal collapses graded?

Answer 24

Yes - graded with an endoscope

Trachea’s will have more than one grade as they will start of normal width, get narrower, return to normal width (e.g. grade normal, 1 ,2 4, 2, normal)

Question 25

What is the medical management for tracheal collapse?

Answer 25

Antitussives
Bronchodilators
Antibiotics
NSAIDS
Corticosteroids (inhaled) -> prevent side effects
Bronchodilators (inhaled)

Question 26

What are the surgical options for tracheal collapse?

Answer 26

Open ring prosthesis

Stenting

Question 27

What are common causes of nasal disease in dogs and how are they investigated?

Answer 27

FB
Tumour
Aspergillosis
Chronic rhinitis
Epistaxis

Investigation
- CT scan
- Rhinoscopy
- Radiography
- Nasal flush

Question 28

What is the common chronic nasal discharge in cats?

Answer 28

Chronic rhinitis

Question 29

What happens in chronic rhinitis in cats?

Answer 29

Inflammation and swelling of the conchae
Increased mucus production
Usually secondary infection, mucopurulent secretion may contain blood
Severe inflammation = loss of conchae

Feline herpesvirus 1 could play a role in chronic nasal inflammation, resulting in destructive rhinitis

Question 30

Which animals commonly present with Fungal rhinitis (Aspergillosis)?

Answer 30

Dogs
Medium to long nose breeds
Less common than neoplasia

Question 31

What is fungal rhinitis (Aspergillosis)?

Answer 31

Disease generally restricted to nasal cavity and sinuses

But is markedly destructive to turbinates

Can erode frontal bones and cribriform plate

Question 32

What are the clinical signs of fungal rhinitis (Aspergillosis)?

Answer 32

Nasal discharge
- Mucopurulent
- Unilateral (progrèss to bilateral)
- Intermittent epistaxis

Ulceration or depigmentation of nasal planum
Pain on palpation
Sneezing
Facial deformity?
Neurological signs?

Question 33

How is fungal rhinitis (Aspergillosis) diagnosed?

Answer 33

History, clinical signs
Blood tests?
- r/o coagulopathy
- Coagulation profile
Diagnostic imaging
- Radiography of nose and sinuses
- CT/MRI
Rhinoscopy
Cytology
Serology?

Look at it -> sample it!

Question 34

How is fungal rhinitis (Aspergillosis) treated?

Answer 34

Challenging to treat -> needs to be aggressive to be successful

Oral antifungal agents (‘azoles)
- Requires prolonged treatment
- Side effects (anorexia, V+) common
- Not recommended

Topical therapy
- Preferred option
- enilconazole, clotrimazole

Choice of delivery method?
- Catheter placement in frontal sinuses via surgery
- Minimally invasive methods
- Use of debridement

Common to debride and then place catheter to allow continuous delivery of anti-fungals.