33 Disorders of the Larynx and Pharynx

Laryngeal paralysis

This is failure of the arytenoid cartilages to abduct during inspiration, creating an upper airway obstruction

Right and left recurrent laryngeal nerves

What innervates the adductor muscles of the larynx?

Dogs

Though cats and dogs may be affected by laryngeal paralysis, which most OFTEN present with clinical signs?

1. Idiopathic

2. ventral cervical lesion

3. anterior thoracic lesion

4. polyneuropathy and polymyopathy

5. endocrinopathy

6. myasthenia gravis

Name some of the more common causes of laryngeal paralysis in animals?

Hypothyroidism

What endocrinopathy disease must be ruled out before diagnosing laryngeal paralysis?

Acetylcholine receptor antibody test

What test allows you to rule out myasthenia gravis when diagnosing laryngeal paralysis?

Idiopathic laryngeal paralysis is part of* generalized neuromuscular or polyneuropathy* complex

What complex is idiopathic laryngeal paralysis part of?

Labrador Retrievers

What dog breed is overrepresented for having laryngeal paralysis?

Older, large breed dogs (normally Labrador Retrievers)

What is the common signalment for laryngeal paralysis?

Laryngeal paralysis (laryngeal disease from the last lecture)

Respiratory distress and stridor are hallmarks of what?

Laryngoscopy

How do you diagnose laryngeal paralysis?

Aspiration pneumonia

note: prognosis is fair to good for laryngeal paralysis itself, mortality is MAINLY caused by aspiration pneumonia

What is the most common complication of laryngeal paralysis?

Under light sedation

How do you do a laryngeal exam? What condition must the animal be in?

DO NOT use opioids or pure mu agonists (hydromorphone)

Sedate with acepromazine, butorphanol or buprenorphine

note: butorphanol and buprenorphine are opioids, but they cause less respiratory depression because they are not pure mu agonists.

What do you have to be careful about when treating laryngeal paralysis in terms of sedation?

DO NOT give temporary tracheostomy tubes bc they increase complications and dogs get hyperthermic because they can't breathe correctly

You have to treat laryngeal paralysis with emergency management of airway obstruction. But what do you have to be careful of when doing this?

Unilateral arytenoid lateralization (tie back)

What is the surgical treatment of choice with laryngeal paralysis?

Cisapride

note: this medication is a prokinetic agent, causes the muscles in the stomach and intestines to contract and relax more effectively, speeding up the digestive process

What medication may be used to decrease risk of aspiration due to laryngeal paralysis?

Boston Terriers, Pugs, Bulldogs, French Bulldogs, Himalayan cats

What breeds are affected by brachycephalic airway syndrome?

Stertor (snorting or snoring)

Is *stertor or stridor* a more common symptom with Brachycephalic Airway Syndrome?

Stertor and GI signs (vomiting and regurgitation)

What signs are common with Brachycephalic Airway syndrome?

1. stenotic nares

2. elongated soft palate

3. hypoplastic trachea (bulldogs)

4. everted laryngeal saccules

Name the 4 anomalies of brachycephalic airway syndromes

Brachycephalic airway syndrome: stenotic airway treated with alarplasty

What is this?

Cat with stenotic nares treated with alarplasty

What is this?

Elongated soft palate that the epiglottis gets caught by

What is this?

Everted saccules

What is this?

Everted laryngeal saccules (edematous and red)

What is this?

Brachycephalic airway syndrome

Clinical signs with this problem are associated with impaired airflow through the upper airways and increase intrathoracic pressure, causing loud upper airway noise associated with obstruction and GI signs of vomiting and diarrhea

Minimize stress factors, surgical correction of abnormalities, and perform procedures early

How do you treat brachycephalic airway syndrome, to overall enhance the passage of air through limited airways?

true

TRUE OR FALSE: laryngeal neoplasia is overall uncommon in cats and dogs

Laryngeal neoplasia (tonsillar squamous cell carcinoma)

What is this?

Laryngeal neoplasia (tumor in middle of larynx = may need to do tracheostomy to treat this)

What is this?

Soft tissue opacity that blends into the soft palate

What is this?

Laryngeal neoplasia

Clinical signs associated with this problem are consistent with upper airway disease like noisy respiration, stridor, increased respiratory effort, and change in voice, though masses may cause dysphagia and aspiration pneumonia

FNA, x-rays, CT/MRI

How do you diagnose laryngeal neoplasia:

Soft tissue in proximal trachea, foreign body

What is this, the animal presents with a history of coughing, not wanting to eat?