Canine tracheobronchial disease

Question 1

normal trachea

Answer 1

extrathoracic-cervical-atmospheric pressure

intrathoracic-pleural pressure

C-shaped cartilage rings

pseudostratified, ciliated epithelial cells

goblet cells

Question 2

Pathology of tracheal collapse

Answer 2

rings lose stiffness and collapse

caused by hypocellular tracheal cartilage (decreased glycoprotein, decreased glycosaminoglycans)

genetic predisposition

Question 3

Secondary factors of tracheal collapse

Answer 3

obesity

endotracheal intubation

cardiac disease

respiratory infection

cervical trauma

airborne irritants

Question 4

tracheal collaps signalment

Answer 4

middle age to older dogs

toy and mini breeds (yorkie)

obesity

Question 5

tracheal collapse clinical signs

Answer 5

chronic, paroxysmal coughing

dry hacking goose-honk cough

exercise intolerance

precipitated by excitement, drinking, heat

dyspnea and cyanosis

Question 6

tracheal collapse PE findings

Answer 6

obesity

sensitive to tracheal palpation

normal thoracic auscultation

cyanosis

hepatomegaly

loud S2, possible murmur

Question 7

DDx of tracheal collapse

Answer 7

chronic bronchitis

kennel cough

laryngeal paralysis

respiratory parasites

tracheal tumor/polyp

tracheal FB

chronic mitral valve disease

canine influenza virus

Question 8

Dx of tracheal collapse

Answer 8

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

Question 9

Tx tracheal collapse

Answer 9

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

Question 10

The mainstay of therapy for tracheal collapse is?

Answer 10

cough suppressants

Question 11

tracheal stents

Answer 11

extraluminal stents for extrathoracic collapse

endoluminal stents-noninvasive, quick, expensive

Question 12

Px for tracheal collapse

Answer 12

cure not possible

progresses in severity

life-long therapy in moderate to severe cases

px poor in severe cases

Question 13

chest rad patterns

Answer 13

interstitial

bronchial

alveolar

nodular/miliary

mixed

Question 14

bronchial pattern

Answer 14

donuts, tramlines

indicates bronchial inflammation

Question 15

Chronic bronchitis

Answer 15

common, chronic inflammatory disease of lower airways

middle to old age dogs

two types: nonspecific (mxied inflammatory) and eosinophilic (allergic)

Question 16

etiology of nonspecific bronchitis

Answer 16

unknown

inhalation of noxious substance?

infectious disease?

immune mediated?

congenital defect?

Question 17

etiology of eosinophilic bronchitis

Answer 17

allergic-seasonal

parasitic-roundworms, lungworms, heartworm disease

Question 18

response of airways to insult

Answer 18

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

Question 19

signalment and hx of chronic bronchitis

Answer 19

>8 years old

toy and small breed dogs

smoking?

chronic cough (>2 months)-deep, harsh, terminal retch

exercise intolerance

possible acute exacerbation of signs

Question 20

PE findings of chronic bronchitis

Answer 20

poss obersity

tracheal sensitivity

prolonged expiratory phase

coarse, diffuse crackles

expiratory wheezes

Question 21

Diagnostic workup of chronic bronchitis

Answer 21

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

Question 22

bronchiectasis

Answer 22

persistent dilation of bronchi

end result of long standing inflammation

loss of normal wall structure

predisposition of infection

irreversible

Question 23

the diagnosis of chronic bronchitis is best made by

Answer 23

hx and PE

Question 24

tx of chronic bronchitis

Answer 24

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

Question 25

px for chronic bronchitis

Answer 25

very good for eosinophilic disease

chronic progressive disease

px poor with pulmonary hypertension

sx can be controlled but not eliminated

Question 26

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?

Answer 26

noncardiac

Question 27

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:

Answer 27

bronchial

Question 28

DDx for chronic bronchitis

Answer 28

tracheal collapse

kennel cough

cardiac disease

heartworm disease

neoplasia

respiratory parasites-Filaroides osleri

Canine influenza

pneumonia

Question 29

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

Answer 29

CBC, Chest radiographs

Question 30

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?

Answer 30

Transtracheal wash

Question 31

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?

Answer 31

eosinophilic bronchitis

Question 32

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?

Answer 32

Glucocorticoids

good px