239 diseases of larynx Flashcards
what is the function of the larynx?
- regulates airflow
- protects lower airway from aspiration during swallowing
- controls phonation
what breeds commonly get acquired laryngeal paralysis?
Golden Retrievers St Bernards Newfoundlands Irish Setters Brittany Spaniels
What is acquired laryngeal paralysis most often caused by?
= most often damage to recurrent laryngeal nerve or intrinsic laryngeal muscles often due to polyneuropathy, polymyopathy, accidental, or iatrogenic trauma or intra/extrathoracic masses
What other proposed aetiologies of laryngeal paralysis?
Congenital:
- genetic trait
- laryngeal paralysis-polyneuropathy complex
Accidental trauma:
- cervical penetrating wounds
- strangulating trauma
Iatrogenic surgical trauma:
- cranial thoracic surgery
- thyroidectomy/parathyroidectomy
- tracheal surgery
- ventral solt
Cervical/intrathoracic neoplasia
- lymphoma
- thymoma
- thyroid carcinoma/ectopic thyroid carcinoma
Neuromuscular disease - geriatric-onset laryngeal paralysis polyneuropathy syndrome (GOLPP) - Endocrinopathy (hypoT, hypoA) immune mediated -infectious - myasthenia gravis - polymyopathy - systemic lupus erythematosus - toxins (lead; organophosphates)
A congenital form of laryngeal paralysis has been reported in what dog breeds…….?
- Bouviers des Flandres
- Siberian Huskies
- Bull terriers
- White coated german shepher dogs
Congenital laryngeal paralysis-polyneuropathy complexes have been described in….?
Dalmations, rottweilers, leonberger dogs, and pyrenean mountain dogs
What are the clinical signs of a dog with laryngeal paralysis?
- arytenoid cartilages and vocal folds remain in paramedian position during inspiration, and upper airway obstruction is
- noisy inspiration and exercise intolerance
- early signs = voice change, mild cough, and gagging.
- severe = resp distress, cyanosis, and collapse +/- dysphagia.
Signs are worsened by exercise, environmental temperature and/or humidity.
What diagnostic tests should be performed for dogs with laryngeal disease?
- physical exam
- ortho and neurological examinations
- CBC
- Biochem
- Urinalysis
- thyroid function -> to start thyroid treatment, but may not improve paralysis
- thoracic rads -> rule out aspiration pneumonia, identify megaoesophagus, pulmonary oedema, cardiac or lower airway abnormalities
- laryngeal exam
What is needed to achieve definitive diagnosis of laryngeal paralysis?
- examination of larynx to document lack or Raytheon I’d abduction during inspiration.
- laryngoscopes, oral video-endoscopic laryngoscopes, trans nasal laryngoscopes (TNL), ultrasound (US, echo), or CT.
- anaesthetic agents can produce false positives
How is acute respiratory distress managed?
- oxygen
- dexamethasone 0.1-1m/kg IV
- acepromazine 0.01-0.02 mg/kg IV
- Buprenorphine 0.005-0.01 mg/kg IV/butorphanol 0.1-0.25mg IV
- ET or tracheostomy if resp distress cannot be abated. Mucus production drastically increases, and it needs to be suctioned from tube.
What are some conservative long-term treatment options fo dogs with unilateral dysfunction?
- reduce daily exercise, owner education, weight loss, and sometimes anti inflammatory drugs
When is surgical intervention indicated?
- bilateral paralysis, poor QOL, severe clinical signs, and time of year
- unilateral arytenoid lateralisation is most used
How common is feline laryngeal disease, and who does it occur in?
- laryngeal disease uncommon in cats, but laryngeal paralysis accounts for 40% of cases.
- most often older cats (9-14years)
What is the cause of feline laryngeal disease?
Mostly unknown
- associated with trauma, neoplastic invasion or iatrogenic damage
How can feline laryngeal paralysis be diagnosed?
- laryngoscopes (direct or endoscopically), echolaryngography