Exam 2 - Diseases of the Pharynx & Larynx Flashcards
what are the most common clinical signs of pharyngeal disease?
stertor, reverse sneezing, gagging, retching, & dysphagia
diseases of the larynx typically result in what clinical signs?
stridor & respiratory distress
T/F: a change in voice is diagnostic for laryngeal disease
true
what is the general pathogenesis of laryngeal disease?
exacerbating event results in a sudden worsening of signs
increased inspiratory effort causes increased negative pressure in the upper airways, & soft tissue is sucked inward
this leads to tissue edema & inflammation
can lead to cyanosis, collapse, & even death
what does stertor indicate?
indicates turbulent flow in the upper airways
what does stridor indicate?
indicates laryngeal disease
what does reverse sneezing indicate?
nasopharyngeal irritation
T/F: respiratory distress is typically in the inspiratory phase
true
to evaluate the pharynx & larynx, what meds can be given?
anesthesia with a short-acting sedative!!! no pre-med!!!
want to achieve a depth where the larynx can be evaluated but deep spontaneous respirations are present
what would be expected of arytenoid movement during normal respiration?
arytenoids should abduct widely & symmetrically during inspiration & return to a resting position during expiration
what is the positioning used for radiographs when evaluating the larynx & pharynx?
head is held with the neck extended without rotation, lateral views, and ventrodorsal views
why is culture from the pharynx or larynx not helpful?
diverse bacterial population is normal
what is obstructive laryngitis?
non-neoplastic infiltration of the larynx with inflammatory cells causing irregular thickening, hyperemia, & swelling - signs of obstruction results
what is the common name for canine infectious respiratory disease complex?
kennel cough
what organisms are associated with causing kennel cough?
canine adenovirus-2
parainfluenza virus
bordetella bronchiseptica
mycoplasma
what is the shedding period of canine adenovirus-2?
<14 days
what is the pathogenesis of canine adenovirus-2?
infects URT including tonsillar crypts & can infect type 2 alveolar cells causing interstitial pneumonia
what is the shedding period for canine parainfluenza virus?
shed for up to 10 days
where does parainfluenza virus infect in the respiratory system?
infection is restricted to the upper respiratory tract
what is the pathogenesis of parainfluenza virus?
denudes the epithelium of cilia
what kind of organism is bordetella bronchiseptica?
gram negative rod
what is the pathogenesis of bordetella bronchiseptica?
colonizes the upper respiratory tract epithelium (trachea, bronchi, bronchioles, & pulmonary interstitium)
paralyzes the cilia decreasing mucociliary clearance & secretes toxins that impair phagocytic function
T/F: mycoplasma can be apart of normal flora in the upper respiratory tract of dogs & cats
true
what is the shedding period for mycoplasma?
chronic shedding for months
what is the pathogenesis of mycoplasma?
colonizes lower respiratory tract epithelium predominantly
in kennel cough, how do you identify the causative agent?
you don’t - clinically indistinguishable
how is kennel cough spread?
aerosolized droplets, dog-dog transmission
T/F: an animal needs to be immunocompromised to get kennel cough
false - highly contagious disease where 50% of the dogs in the environment are affected
what is the incubation period of kennel cough?
3-10 days
T/F: an animal with kennel cough can have preclinical shedding
true
what is the shedding period for kennel cough?
2 weeks-3 months post infection
what is the most common presentation of kennel cough?
BAR, honking cough, may gag/retch when coughing, if present, serous nasal discharge, & a change in bark from laryngitis/tonsilitis
how long is an animal affected by kennel cough?
resolves after 7-14 days with no long term consequences
when can there be complications associated with kennel cough in dogs?
unvaccinated dogs, very young dogs, poor overall health
if kennel cough becomes complicated, what clinical signs may be seen? what disease do you need to rule out?
progressive cough, lethargy, fever, mucopurulent nasal discharge
rule out distemper!!!
how is kennel cough diagnosed?
presumptive diagnosis based on clinical signs & recent exposure, radiographs if pneumonia is suspected, PCR panels are available but often not necessary in most cases
when may PCR be pursued in an animal with kennel cough?
trying to document an outbreak
what should be included in the supportive care for kennel cough?
outpatient when possible - isolate them!
feed warm, soft food, appetite stimulants, clean nasal discharge, nebulize, & avoid antitussives in complicated cases
what are the proposed benefits using antibiotics for a kennel cough patients?
may decreased symptomatic days & risk of secondary pneumonia - 10 day course of doxycycline, amoxicillin-clavulanate, trimethoprim-sulfa
why should you avoid cough suppressants in pneumonia patients?
may impede airway clearance
how is pneumonia treated?
if patient is stable - perform an airway wash for culture & susceptibility
empirical antibiotics while results are pending - doxycycline & amoxicillin-clavulanate, & may require hospitalization
T/F: glucocorticoids shorten the duration of clinical signs & bronchodilators improve clinical signs in patients with kennel cough
false
how is kennel cough prevented?
vaccines!! IN vaccine with bordetella and/or CPiV given atleast 1 week prior to boarding & within 6 months of boarding
why is the vaccine for canine influenza virus used?
killed vaccine used to reduce clinical signs & reduce viral shedding
what is the series of canine influenza vaccines?
2-dose initial series & annual booster
if there is an outbreak of kennel cough in your clinic, what should be your next steps?
admit only dogs that are up-to-date on vaccines
isolate affected dogs immediately
clean everything & ensure adequate ventilation
ideally, close the population for 2 weeks
treat animals symptomatically
what is the minimum database for the coughing patient?
thoracic rads, heartworm test, & CBC
what may coughing be mistaken for in dogs and cats?
dogs - owner may mistake cough as normal
cats - hairballs
what is coughing?
sudden expulsion of air, glottis is closed, & used to expel material from the airway
what are some examples of differentials for a non-productive cough?
post-nasal drip, respiratory irritant, neoplasia, foreign body, pleural effusion
what are some examples of differentials for a productive cough?
cardiogenic edema, non-cardiogenic edema, pneumonia
what is hemoptysis?
coughing up blood
what are some examples of differentials for hemoptysis?
heartworm disease, neoplasia, PTE, fungal disease, trauma, or systemic bleeding disorder
tracheal collapse generally affects what animals?
small breed dogs
when should antitussives be used?
for non-productive coughs to palliate & break the cough cycle
what is the mechanism of action of opiods used as antitussives?
opiods act at peripheral receptors & centrally at the cough center
what are 2 options of opioids that can be used for antitussives?
oral hydrocodone & oral butorphanol
why would expectorants & mucolytics be used in the coughing patient?
loosen mucus congestion
why should you not use acetylcysteine in cats?
causes bronchospasm
why not used guaifenesin in cats?
some forms contain acetaminophen
what are b1 & b2 receptors responsible for?
b1 - heart rate & strength of contraction
b2 - bronchodilator
what are the side effects associated with bronchodilators?
tachycardia, agitation, & gi upset
what are some examples of b-receptor agonists used?
albuterol - oral or inhaled
terbutaline - oral or injectable, selective B2
what is the mechanism of action for theophylline extended-release? how does it help your patient
unknown - but may improve the strength of diaphragmatic contraction & respiratory muscle strength & improve mucociliary clearance
what drug should be avoided when using theophylline extended release?
enrofloxacin
T/F: theophylline can be used in both dogs & cats
false - only dogs
what are some examples of corticosteroids & sedatives that can be used in coughing patients?
corticosteroids - injectable dexamethasone, oral pred, inhaled fluticasone, & temaril-p
sedatives - trazodone, butorphanol, gabapentin
how is a diagnosis of obstructive laryngitis made?
upper airway exam & laryngeal biopsy
what is the prognosis for an uncomplicated case of kennel cough?
recovery within 2 weeks
