Canine tracheobronchial disease Flashcards
normal trachea
extrathoracic-cervical-atmospheric pressure
intrathoracic-pleural pressure
C-shaped cartilage rings
pseudostratified, ciliated epithelial cells
goblet cells
Pathology of tracheal collapse
rings lose stiffness and collapse
caused by hypocellular tracheal cartilage (decreased glycoprotein, decreased glycosaminoglycans)
genetic predisposition
Secondary factors of tracheal collapse
obesity
endotracheal intubation
cardiac disease
respiratory infection
cervical trauma
airborne irritants
tracheal collaps signalment
middle age to older dogs
toy and mini breeds (yorkie)
obesity
tracheal collapse clinical signs
chronic, paroxysmal coughing
dry hacking goose-honk cough
exercise intolerance
precipitated by excitement, drinking, heat
dyspnea and cyanosis
tracheal collapse PE findings
obesity
sensitive to tracheal palpation
normal thoracic auscultation
cyanosis
hepatomegaly
loud S2, possible murmur
DDx of tracheal collapse
chronic bronchitis
kennel cough
laryngeal paralysis
respiratory parasites
tracheal tumor/polyp
tracheal FB
chronic mitral valve disease
canine influenza virus
Dx of tracheal collapse
high suspicion based on hx and PE
chest rads-DV narrowing of tracheal segment, inspiratory and expiratory films needed
flouroscopy-demonstrates dynamic collapse, can see bronchi collapse, dog must cough during procedure
tracheobronchoscopy-narrow, cresent chape lumen, collapse of mainsteam bronchi, req anes
Tx tracheal collapse
weight loss if indicated
avoid excitement, stress
use harness
anti-tussives-hyodrocodone, butorphanol, sedation may occur
bronchodilators-helpful if concurrent bronchitis
glucocorticoids-reduce tracheitis, anti-infl dose
emergency therapy for dyspnic patients
sedative?
surgical therapy-for severe refractory cases
The mainstay of therapy for tracheal collapse is?
cough suppressants
tracheal stents
extraluminal stents for extrathoracic collapse
endoluminal stents-noninvasive, quick, expensive
Px for tracheal collapse
cure not possible
progresses in severity
life-long therapy in moderate to severe cases
px poor in severe cases
chest rad patterns
interstitial
bronchial
alveolar
nodular/miliary
mixed
bronchial pattern
donuts, tramlines
indicates bronchial inflammation
Chronic bronchitis
common, chronic inflammatory disease of lower airways
middle to old age dogs
two types: nonspecific (mxied inflammatory) and eosinophilic (allergic)
etiology of nonspecific bronchitis
unknown
inhalation of noxious substance?
infectious disease?
immune mediated?
congenital defect?
etiology of eosinophilic bronchitis
allergic-seasonal
parasitic-roundworms, lungworms, heartworm disease
response of airways to insult
hypertrophy of airway epithelium
erosion or ulceration of mucosa
hypertrophy of airway goblet cells and mucosal glands causing increased mucus
edema and inflammatory cell infiltration of smooth muscle and mucosa
unchange or hypertrophied smooth muscle
signalment and hx of chronic bronchitis
>8 years old
toy and small breed dogs
smoking?
chronic cough (>2 months)-deep, harsh, terminal retch
exercise intolerance
possible acute exacerbation of signs
PE findings of chronic bronchitis
poss obersity
tracheal sensitivity
prolonged expiratory phase
coarse, diffuse crackles
expiratory wheezes
Diagnostic workup of chronic bronchitis
lab-normal with eosinophilia
chest rads- may be normal, bronchial pattern, bronchiectasis in advanced cases, alveolar infiltrate poss
bronchoscopy-expensive
cytology and culture of airway fluid-BAL ideal, TTW, mixed inflammatory response (PMNs) alveolar macrophages (normal), mucus, eosinophils
bronchiectasis
persistent dilation of bronchi
end result of long standing inflammation
loss of normal wall structure
predisposition of infection
irreversible
the diagnosis of chronic bronchitis is best made by
hx and PE
tx of chronic bronchitis
reduce inflammation-glucocorticoids-high dose at first, then low dose long term, poss inhalant therapy
bronchodilators-indicated with exercise intolerance and/or wheezes on auscultation (albuterol, terbutaline, theodur, aminophylline)
antitussives-use sparingly
abx-base on C&S
weight loss
avoid airway irritants
address dental disease
neublization
px for chronic bronchitis
very good for eosinophilic disease
chronic progressive disease
px poor with pulmonary hypertension
sx can be controlled but not eliminated
6 yo FS border collie
cough for at least 3 weeks with no response to abx
vax current, on HW prevent, cough worsens with exercise, during thed ay, dry but poss wheezing
PE: Normal BCS, normal TPR, no coughing with tracheal palpation, normal cardiac auscultation, crackles ausculted bilaterally on inspiration.
Cardiac or noncardiac?
noncardiac
6 yo FS border collie
cough for at least 3 weeks with no response to abx
vax current, on HW prevent, cough worsens with exercise, during thed ay, dry but poss wheezing
PE: Normal BCS, normal TPR, no coughing with tracheal palpation, normal cardiac auscultation, crackles ausculted bilaterally on inspiration.
localize cough:
bronchial
DDx for chronic bronchitis
tracheal collapse
kennel cough
cardiac disease
heartworm disease
neoplasia
respiratory parasites-Filaroides osleri
Canine influenza
pneumonia
6 yo FS border collie
cough for at least 3 weeks with no response to abx
vax current, on HW prevent, cough worsens with exercise, during thed ay, dry but poss wheezing
PE: Normal BCS, normal TPR, no coughing with tracheal palpation, normal cardiac auscultation, crackles ausculted bilaterally on inspiration.
Test to reccommend
CBC, Chest radiographs
6 yo FS border collie
cough for at least 3 weeks with no response to abx
vax current, on HW prevent, cough worsens with exercise, during thed ay, dry but poss wheezing
PE: Normal BCS, normal TPR, no coughing with tracheal palpation, normal cardiac auscultation, crackles ausculted bilaterally on inspiration.
Lab: normal chem, negative HW, leukocytosis with eosinophilia, rads: diffuse bronchial pattern
Next diagnostic step?
Transtracheal wash
6 yo FS border collie
cough for at least 3 weeks with no response to abx
vax current, on HW prevent, cough worsens with exercise, during thed ay, dry but poss wheezing
PE: Normal BCS, normal TPR, no coughing with tracheal palpation, normal cardiac auscultation, crackles ausculted bilaterally on inspiration.
Lab: normal chem, negative HW, leukocytosis with eosinophilia, rads: diffuse bronchial pattern
TTW results: increased nucleated cell count (eosinophils), increase mucus, no organisms seen
Diagnosis?
eosinophilic bronchitis
6 yo FS border collie
cough for at least 3 weeks with no response to abx
vax current, on HW prevent, cough worsens with exercise, during thed ay, dry but poss wheezing
PE: Normal BCS, normal TPR, no coughing with tracheal palpation, normal cardiac auscultation, crackles ausculted bilaterally on inspiration.
Lab: normal chem, negative HW, leukocytosis with eosinophilia, rads: diffuse bronchial pattern
TTW results: increased nucleated cell count (eosinophils), increase mucus, no organisms seen
Best tx and px?
Glucocorticoids
good px
