Laryngeal Paralsysis And Nasopharyngeal Disorders Flashcards
What is the normal function of the larynx ?
Regulate airflow
Project trachea from aspiration during swallowing
Control phonation
What nerve innervates all but 1 of the intrinsic laryngeal muscles. Where does it branch from?
Caudal laryngeal nerve, from the recurrent laryngeal, from the vagus
Contraction of what muscle results in the abduction of the arytenoid cartilages?
Cricoarytenoideus dorsalis muscle
What is the etiology of laryngeal paralysis?
Aqueduct in dogs- dysfunction of recurrent laryngeal nerve or intrinsic laryngeal muscle
Polyneuropathy
Polymyopathy
Trauma
Mass
Idiopathic
Geriatric onset of laryngeal paralysis-polyneuropathy is most common in what breed?
Labrador retrievers
Congenital LP has been reported in what breeds?
Bouviers does Flanders
Bull terriers
Huskies
What is the signalment for laryngeal paralysis?
Older and giant breeds
Labrador retrievers, golden retriever, St. Bernard, Newfoundland, Irish setter, Brittany spaniel
How do dogs with laryngeal paralysis present ?
Noisy inspiration
Exercise intolerance
Voice change
Coughing/gagging (low grade laryngospasm or tracheitis)
Signs of laryngeal paralysis are often exacerbated by what conditions?
Heat
Humidity
Exercise
Stress
Some dogs with laryngeal paralysis can also present with pelvic limb defects and esophageal dysfunction. What would be the cause ?
Polyneuropathy
T/F: stridor localizes a respiratory problem to the larynx or extrathoracic trachea
True
What causes stridor and when doe it occur?
Loud respiratory noise that occurs because airflow is obstructed
During inspiration
What diagnostics do you do on an old large breed dog presenting for noisy inspiration, exercise intolerance, and coughing/gaging ?
Neurological and orthopedic exam
Minimum database and thyroid testing
Thoracic radiographs —>evaluate for aspiration pneumonia, megaesophagus, cardiac disease, and lower airway disease
Definitive diagnosis of laryngeal paralysis requires laryngeal exam
T/F: dogs with severe laryngeal paralysis can develop non-cardiogenic pulmonary edema
True
What is the treatment for laryngeal paralysis?
If unilateral —> conservative treatment
-weight loss and lifestyle/environmental modifications
Bilateral with moderate to severe clinical signs —> surgical
-unilateral arytenoid lateralization
A dog comes into your clinic in severe respiratory distress due to laryngeal paralysis. What do you do?
Supplemental O2 Corticosteroid Sedation Minimize stress and handling Cooling if hyperthermia
Severe—> incubated and mechanically ventilate (may bee emergency surgery)
What is the cause of laryngeal paralysis in cats?
Neoplastic infiltration
Trauma
Iatrogenic (post-thyroidectomy)
Idiopathic
T/F: clinical signs can be severe in cats even with unilateral paralysis
True
Tiny cat, tiny trachea
Cats with laryngeal paralysis are managed like dogs
What are the primary defects in brachycephalic airway obstruction syndrome (BAOS)?
Stenotic nares
Elongated soft palate
Can also be present: narrowed nasal cavities, distorted turbinates, aberrant turbinates, macroglossia, thickened soft palate, redundant pharyngeal folds, tracheal hypoplasia
What defects can arise secondary to brachycephalic airway obstruction?
Exerted laryngeal ventricles (saccules)
Laryngeal collapse
Bronchial collapse
T/F: concurrent gastrointestinal diseases are common with brachycephalic airway obstruction syndrome
True
- esophageal deviation
- gastroesophageal reflux
- gastric stasis
- pyloric hypertrophy
- inflammation
What is the pathophysiology of brachycephalic airway obstruction?
Narrowed and deformed airways result in increased resistance and turbulent airflow
—> neg inspiratory pressure draws tissues into airway lumen
—>create inflammation/swelling/edema
—>exacerbate airflow obstruction —> increased velocity and turbulent flow —> worsen swelling —> secondary changes
What is the signalment of BAOS?
Any brachycephalic cat or dog
How can patients with BAOS present?
Noisy breathing
Snoring
Gagging/coughing
Exercise/heat/stress intolerance
Stertor
Stridor
Inspiration dyspnea
Cyanosis, syncope, and death
Respiratory distress
How is brachycephalic airway obstruction syndrome diagnosed?
Stenotic nares on PE
Cervical and thoracic radiographs to evaluate tracheal, bronchopulmonay abnormalities, and hiatal hernia
Laryngeal exam for abnormalities of the oropharynx and larynx
Endoscopy or CT —> diagnose nasal, pharyngeal, largyneal, tracheal, bronchial abnormalities
How do you treat BOAS?
Surgical correction
- rhinoplasty
- soft palate reception
- laser-assisted tubinectomy
- ventriculectomy
To avoid complications, surgery is indicate early in disease
Client education and environmental management —> avoid heat, humidity, strenuous exercise, over excitement, and stress
Treat GI disease if present
Why do you commonly see otitis with nasopharyngeal disorders?
Linked to middle ear via auditory tube
What is a nasopharyngeal polyp?
Fibromuscular connective tissue arising from musical lining of the nasopharynx
T/F: polyps are more common in dogs than in cats
False
Cats more commonly
What are causes of nasopharyngeal polyps?
Cat: congenital defect, chronic inflammation, viral infection
Dog: usually secondary to chronic inflammation/ rhinitis
How do animals with nasopharyngeal polyps present?
Stertor (localized to upper airway)
May present in respiratory distress —> open mouth breathing and cheek puffing
Nasal discharge Excessive swallowing Gagging Coughing Dysphasia Voice/phonation change
Reverse sneezing (dog)
What areas of the respiratory system does sneezing and reverse sneezing localize respiratory diseases?
Sneezing (expiratory) —> nasal or sinus disease
Reverse (inspiratory) —> nasopharyngeal, caudal nasal, or sinus disease
What is the treatment of nasal polyps?
Traction-avulsion +corticosteroid
OR
Ventral bulla osteotomy if bulla is involved
How do you diagnose a nasal polyp?
Tentative: General anesthesia, retract soft palate rostrally to visualize polyp
Requires histopathology to definitively diagnose polyp vs neoplasia
Clinical signs usually seen with foreign body?
Reverse sneezing Pawing at face Excessive swallowing Gagging Dysphasia Coughing Nasal discharge Halitosis
How can you diagnose foreign bodies?
Radiographs—> radiopaque
Direct visualization
Endoscopy
CT
What are causes of nasopharyngeal stenosis?
Regurgitation (esp under anesthesia)
Chronic inflammation
Post-surgical
Trauma
Congenital anomaly
Mass
What is the treatment for nasopharyngeal stenosis ?
Balloon dilation most effective
What is the most common cause of fungal rhinitis in cats?
Cryptococcus
Other possible: aspergillus and rhinosporidium
What is the signalment for feline fungal rhinitis?
Usually younger but can be any age
Clinical signs of feline fungal rhinitis?
Sneezing and nasal discharge (mucoid/purulent)
Polyploid masses in nares and ulcers/nodules on planum or bridge (crypto)
Mass causes—> decreased or absent nasal airflow, exopthalmos, facial asymmetry, stertor, mass/ulcer in pterygopalantine fossa
What diagnostics do you do if you suspect a fungal rhinitis?
MDB
FeLV/FIV —> predisposing cause
Thoracic radiographs
Cytology and culture of nasal discharge Serology CT Rhinoscopy with biopsy Dental probing—> periodontal disease/tooth root abcess
How can CT help differentiate between neoplasia and cryptococcus?
Neoplasia usually causes turbinate lysis/bony destruction, crypto does not
How do you treat cryptococcus??
Ora fluconazole (or itraconazole—> more adverse effects) —> treat until antigen latex agglutination test is 0 and then recheck a month after treatment
Can debulk granuloma if severe
What are the adverse effects of fluconazole?
Inappetance
Hepatotoxicity
How do you treat aspergillus?
Oral posaconazole or itraconazole
What is the prognosis of fungal rhinitis?
Good if no CNS involvement
Poor for sino-orbital aspergillus (more invasive and usually affects CNS)
What is the signalment for chronic rhinosinusitis?
Unknown
- feline herpesvirus 1 has been implicated
- may have some bacterial involvement
What is the signalment of chronic rhinosinusitis?
Cat
Any age
Sneezing and nasal discharge
Nasal airflow is usually preserved
T/f: Chronic rhinosinusitis is a diagnosis of exclusion
True
MDB, FeLV/FIV, thoracic radiographs
CT: variable degree of turbinate lysis and increased fluid density
Laryngoscopes, rhinoscopy, and biopsy to rule out other causes
Dental probing to rule out dental disease
What is the treatment of chronic rhinosinusitis ?
Antibiotic -choice based on culture or historical data (usually doxycyline)
Anti-inflammatory —> NSAID or glucocorticoids
Antiviral —> lysine or famciclovir
Treat nasal discharge—> nasal flush, humidification, N-acetylcystine
What are the common nasal tumor types?
Lymphoma Adenocarcinoma Squamous cell carcinoma a Undifferentiated carcinoma Fibrosarcoma
What is the most common cause of canine fungal rhinosinusitis?
Aspergillus
What is the signalment of nasal aspergillus in dogs?
Young to middle age
Dolichocephalic
Clinical signs of nasal aspergillosis in dog?
Nasal discharge
Sneezing
Facial pain, depigmentation, and ulceration may be present
How do you treat nasal aspergillosis in dogs?
Topical infusion if cribriform plate is intact —> clotrimazole or enilconazole
Oral antifungal agent alone if cribriform plate is NOT intact —> itraconazole or terbinafine for 3-6months
What are suspected causes/contributing factors to idiopathic lymphoplasmic rhinitis?
Abberant immune response
Inhaled allergen and irritant
Hypersensitivity to native organisms
What is the signalment for idiopathic lymphoplasmic rhinitis ?
Young to middle aged dolichocephaic and mesaticephalic large breeds and dachshunds
—> dachshunds commonly have dental disease, rule this out
What are clinical signs associated with idiopathic lymphosplama cystic rhinitis?
Uni or bilateral nasal discharge, mucoid/mucopurulent
Epistaxis
Excessive mucus/mucosal edema May obstruct airflow
What must you rule out to diagnose idiopathic lymphoplasmacytic rhinitis?
Fungal
Neoplasia
Chronic foreign body
What is the treatment of idiopathic lymphoplasmacytic rhinitis?
Avoidance of smoke and potential allergens
Long term antibiotic with immunomodulatory effects + NSAID
-doxycline and azithromycin + piroxicam
In refractory cases, itraconazole may be effective
What is the prognosis of idiopathic lymphplasmacytic rhinitis?
Fair, cure rarely achieved
Frustrating if discharge can not be controlled
