Tracheal Collapse, Laryngeal paralysis, and BAOS Flashcards
What is a primary cause of tracheal collapse?
Born with weak cartilage rings deficient in glycosaminoglycan, chondroitin, and calcium
What are secondary causes of tracheal collapse?
- Increased pressure on the trachea in association with other chronic resp disease (Ex: Chronic bronchitis, idiopathic pulmonary fibrosis)
True or False: Tracheal collapse is more commonly seen in dogs than cats
True
Collapse of the cervical trachea occurs during ______________
Inspiration
Collapse of the thoracic trachea occurs during ______________
Expiration
What respiratory sounds can be heard on inspiration and expiration from a patient with tracheal collapse?
- “Honking” on expiration (most common CS), can have terminal retch
- Loud “rattling” or stridor during inspiration
What breeds are more at risk for tracheal collapse?
Small breeds
- Yorkie, pomeranian, poodle, maltese, chichi, pug
Chronic “honking” sound that is precipitated by excitement/activity or drinking water is a good indicator of which of the following?
A. Asthma
B. Chronic bronchitis
C. Tracheal collapse
D. Spirocerci lupi infection
C. Tracheal collapse
What physical exam findings can be present in a patient with tracheal collapse?
- Cough elicited on tracheal palpation
- “Honking” or rattling
- Stridorous sounds on tracheal auscultation
- Hyperthermic if in resp distress
- Signs of PH if severe
What is the first diagnostic performed following a complete PE in a patient suspect of tracheal collapse?
3 view thoracic and cervical rads on inspiration and expiration
What test is needed to obtain a definitive diagnosis of tracheal collapse?
- Fluoroscopy or tracheoscopy
- Bronchoscopy to rule out other causes
What is the drug treatment protocol for a stable patient with tracheal collapse?
- Short term tapering dose of Prednisone
- Lifelong cough suppressant (Hydrocodone), only to be used as needed for flare ups
- Sedative to be given for stressful events
- Abx if 2ndary infection
- +/- bronchodilator
Other than drugs, what treatments can reduce clinical signs associated with tracheal collapse
- Weight loss!!!
- Avoid hot climates
- Avoid strenuous exercise
- No collar around neck
What is the treatment protocol for a patient with tracheal collapse who is refractory to drug therapy or has severe dyspnea?
- Intraluminal stenting or surgical prostheses only in patients with severe dyspnea or failure to respond to meds
Tx of resp distress: - Sedation
- O2
- Dexamethasone
- Cooling if hyperthermic
List the main functions of the larynx
- Regulates airflow
- Protects trachea from aspiration during swallowing
- Controls phonation (voice)
List the common etiologies associated with acquired laryngeal paralysis
- Polyneuropathy
- Polymyopathy
- Trauma
- Mass (neoplasia, granuloma)
List the breeds associated with early onset laryngeal paralysis-polyneuropathy
- Rottie
- Dalmations
- Pyrenese mountain dogs
- Leonberger dogs
List the breeds associated with geriatric onset laryngeal paralysis-polyneuropathy
Lab retrievers
List the breeds associated with congenital laryngeal paralysis
- Bouviers des flanders
- Bull terriers
- Huskies
- White coated GSD
True or False: Laryngeal paralysis is usually more common in older small breed dogs
False - older LARGE BREED dogs
What can be found on physical exam from a dog with laryngeal paralysis?
- Stridor on inspiration, localized to the larynx or extrathoracic trachea, heard during activity or panting
- Can be hyperthermic if in resp distress
- Voice change, coughing or gagging
What abnormal respiratory sound is commonly heard in patients with laryngeal paralysis?
Stridor - high pitched, continuous URT sound
What is a common complication of laryngeal paralysis?
A. Hypothermia
B. Aspiration pneumonia
C. Stricture formation
D. Tracheal collapse
B. Aspiration pneumonia
What drug is given to stimulate respiration during a sedated laryngeal exam?
Doxapram
(Helps reduce drug related lack of motility)
Why is a complete neuro exam important in dogs with laryngeal paralysis?
Common cause of laryngeal paralysis is polyneuropathy - can see pelvic limb deficits + esophageal dysfunction
What diagnostics would you perform in a dog with suspect laryngeal paralysis?
- MDB, thyroid testing
- Thoracic rads (evaluate for aspiration pneumonia + megaesophagus, severe LP can cause NCPE)
- Sedated laryngeal exam for definitive diagnosis
What can be seen on a sedated laryngeal exam from a patient with laryngeal paralysis
- Lack of abduction of arytenoids during inspiration (can’t open and let air into trachea)
When is surgical intervention indicated for patients with laryngeal paralysis?
- Reserved for bilateral LP and moderate or severe clinical signs
(unilateral arytenoid lateralization-permanent opening of the larynx. Con: more at risk for aspiration pneumonia)
What is the name of the surgical procedure performed on patients with severe bilateral laryngeal paralysis?
unilateral arytenoid lateralization (permanent opening of the larynx)
Con: more at risk for aspiration pneumonia
List 3 upper respiratory tract conditions in DOGS where you would recommend the following conservative treatments: Avoid heat/humidity, strenuous exercise, over-excitement, and stress
- Laryngeal paralysis
- Tracheal collapse
- BAOS
(true for cats with laryngeal paralysis too)
Weight loss is strongly recommended in patients with which of the following upper respiratory tract diseases?
A. Laryngeal paralysis
B. Tracheal collapse
C. Chronic bronchitis
D. All of the above
D. All of the above
What is the treatment protocol for a patient in respiratory distress due to severe laryngeal paralysis?
- Oxygen
- Corticosteroid (Dexamethasone)
- Sedation (acepromazine, butorphanol)
- Cooling if hyperthermic
True or False: Laryngeal paralysis is uncommon in cats, but when laryngeal disease is present, its usually due to laryngeal paralysis
True
True or False: Dogs with laryngeal paralysis usually present with worse clinical signs than cats
False
CS can be more severe in cats, even with unilateral paralysis (smaller orifice than dogs)
List the causes of laryngeal paralysis in cats
- Neoplastic
- Trauma
- Iatrogenic (post-thyroidectomy)
List the primary defects of BAOS
1. Stenotic nares
2. Elongated soft palate
3. Tracheal hypoplasia
4. Distorted turbinates
List the secondary defects from BAOS
Everted laryngeal sacs, laryngeal collapse, bronchial collapse
Concurrent GI disorders are common: esophageal deviation, gastroesophageal reflux, GI stasis, pyloric hypertrophy, inflammation
What is the function of nasal conchae?
Cleans and thermoregulates air
(brachycephalics have messed up nasal conchae - can’t cool air - prone to overheating)
Why are patients with BAOS instructed to avoid heat, stress, and strenuous exercise?
Heat/stress/exercise → Increased velocity of airflow → increased turbulence in airways → worsens inflammation, swelling, and edema
What abnormal respiratory sound is most commonly heard in patients with BAOS?
A. Stertor
B. Stridor
C. Wheezing
D. Crackles
A. Stertor “snoring”
- discontinuous, low pitch URT sound localized to nasal cavity/pharynx
+/- can hear stridor
What GI signs are common in patients with BAOS?
Regurg, vomiting
What is the treatment protocol for a patient in respiratory distress due to BAOS?
- Oxygen
- Corticosteroid (Dexamethasone)
- Sedation (acepromazine, butorphanol)
- Cooling if hyperthermic
(same tx for resp distress due to laryngeal paralysis)
What is the definitive treatment to fix a patient with BAOS and further prevent life-threatening respiratory distress?
Requires surgery:
- Rhinoplasty
- Soft palate resection (palatoplasty)
