Bronchial Diseases

Question 1

What does the cough reflex do?

Answer 1

• Removes accumulates mucous
• Assists mucocilliary clearance
• Expels inhaled particulate material
• Protects against inhaling particles

Question 2

What receptors help with coughing?

Answer 2

• Mechanoreceptors - in larger airways
• Chemoreceptors - in medium airways
• none in bronchioles or alveoli

Question 3

What are Ddx for coughing?

Answer 3

• Compression of mainstem lobar bronchi
• Stimulation of cough receptors
• Excessive mucus / fluid / inflammation

Question 4

What can cause compression of mainstem lobar bronchi?

Answer 4

– Left atrial enlargement
– Tracheobronchial / Bronchial Lymphnode enlargement
– Neoplasia

Question 5

What can cause stimulation of cough receptors?

Answer 5

• Laryngeal disorders
• Tracheal disorders
• Bronchial disorders

Question 6

What can cause excessive mucus/ fluid/ inflammation?

Answer 6

– (usually soft / moist / ineffectual cough)
– Pneumonia
– Bronchopneumonia
– Pulmonary oedema

Question 7

What occurs with HR, heart rhythm with cardiac disease?

Answer 7

• Normal or increased HR
• Regular sinus rhythm, sinus tachycardia or arrhythmias

Question 8

What occurs with HR, heart rhythm with respiratory disease?

Answer 8

• normal or decreased HR
• Sinus arrhythmia (unless v stressed)

Question 9

What history should be collected with a coughing patient?

Answer 9

• Environment
• Worming history
• Travel history
• Recent events / illnesses / changes
• Any other signs?
• How long coughing?
• Onset?
• Description of the cough. When worse?
• Is the cough really a cough?
• Any change in bark?
• Does the dog sleep normally?

Question 10

What should be done on clinical exam?

Answer 10

• Observation (respiratory rate / pattern / any dyspnoea /
  any spontaneous coughing)
• Detailed clinical examination
• Listen to all lung areas during normal quiet (non-panting) respiration. Identify adventitious respiratory
  sounds.
• Listen to and palpate upper respiratory tract
• Percussion
• Thoracic compressibility (cats)
• Attempt to induce a cough – auscultate following cough

Question 11

What characterises chronic bronchitis?

Answer 11

• Excessive mucus production
• Increased goblet cell numbers
• Hyperplasia of submucosal glands
• Damage to cilia
• Loss of ciliated epithelium
• Squamous metaplasia of mucosa
• Secondary infections = common

Question 12

What breeds are more susceptible to chronic bronchitis? how is the disease treated?

Answer 12

• Small breed / toy breed dogs
• Guarded prognosis - irreversible change - aim is to manage condition

Question 13

What investigation should be done?

Answer 13

• Thoracic radiographs
• Haematology
• Bronchoscopy
• Bronchoalveolar lavage to obtain samples for cytology / bacteriology / parasitology

Question 14

When is bronchial collapse seen?

Answer 14

• May be secondary to other primary respiratory conditions
• Chondromalacia
• Wheezy cough
• Not just small breed dogs

Question 15

What are respiratory parasites in small animals?

Answer 15

• Oslerus (Filaroides) osleri - forms nodules (=collapse)
• Crenosoma vulpis (fox lung worm) - seen on tracheobronchoscopy
• Aelurostrongylus abstrusus (cats)

Question 16

How much fluid should you use for a BAL?

Answer 16

• about 0.5ml / kg
• Should be able to aspirate 50% of fluid

Question 17

What cells would be seen on BAL cytology?

Answer 17

• Ciliated columnar epithelial cells
• Goblet cells
• Macrophages (70%)
• Neutrophils (20%)
• Lymphocytes (10%)
• Eosinophils (<20-25%)
• Simonsiella = oral contamination

Question 18

What is seen on BAL cytology of chronic bronchitis?

Answer 18

• Cytology:
• Increased mucus ++
• Increased neutrophils, macrophages
• Possibly squamous metaplasia of normal ciliated
  columnar epithelial cells (CCECs)
• Presence of bacteria / particulate matter
• Submit for Bacteriological culture

Question 19

How would you manage chronic bronchitis?

Answer 19

• Weight control
• Harness>collar/lead
• Avoid irritants / smoking environment
• Excess of Mucus!
• Mucus is easier to shift if hydrated
• Avoid very dry environments (CH)
• Nebuliser
• Spend time in bathroom during owners
  shower / bath!!

Question 20

How would you treat chronic bronchitis?

Answer 20

• Bronchodilators - theophylline / terbutaline
• Anti-inflammatory - glucocorticoids (steroids)
• +/- Anti-tussives

Question 21

What do bronchodilators do?

Answer 21

• Reduce spasm of lower airways
• Reduce intra-thoracic pressures
• Reduce tendency of larger airways to collapse
• Improve diaphragmatic function
• Improves muco-ciliary clearance
• Inhibit mast cell degranulation (reduced release of mediators of bronchoconstriction)
• Prevent microvascular leakage

Question 22

What do glucocorticoids do?

Answer 22

• Broncho-dilatory
• Anti-inflammatory
• Inhibit both prostaglandin & leukotriene synthesis
• Potentiate beta-2 adrenergic activity
• Reduce leukocyte accumulation
• Induce lymphopenia & eosinopenia
• Reverse increased vascular permeability
• Alter macrophage function
• Inhibit fibroblast growth
• Modulate the immune system

Question 23

What antibiotics could be used for respiratory infections?

Answer 23

• Potentiated amoxycillin
• Cephalexin
• TMP sulphonamides
• Fluoroquinoloes
• Doxycycline
• Clindamycin
• Metronidazole

Question 24

What is Eosinophilic Lung Disease (ELD) aka Eosinophilic Bronchopneumopathy (EBP) aka Pulmonary Infiltrate with Eosinophils (PIE)

Answer 24

• Spectrum of disease from “chronic bronchitis” to pulmonary granulomatous disease
• Usually a mixture of bronchial and interstitial pulmonary involvement
• Usually young dogs, large breeds
• Presumed hypersensitivity to inhaled allergens (or parasites e.g. migrating Toxocara canis)
• > 25% eosinophils

Question 25

What is Tx of EBP / PIE?

Answer 25

• Prednisolone - 2mg/kg/day

Question 26

What is the most common cause of coughing in cats?

Answer 26

• Inflammatory airway disease / allergic airway disease

Question 27

What is seen with feline asthma?

Answer 27

• Affected cats present with a cough
• Allergic airway disease
• Reactive bronchoconstriction may also result
• Can have air trapping and severe dyspnoea
• Expiratory dyspnoea (bronchoconstriction affects expiratory phase more than inspiratory)
• May auscultate expiratory wheezes

Question 28

How would you treat a dyspnoeic cat with feline asthma?

Answer 28

• Minimise stress
• Provide humidified oxygen (in incubator; oxygen cage)
• Give IV steroids (e.g. dexamethasone 1 mg/kg)
• Bronchodilators e.g. Terbutaline (0.01 mg/kg IM or IV)
• Consider MDI admin. of bronchodilators (salbutamol)
• Severe, life-threatening distress: Adrenaline (0.1ml of 1:1000 IV or via ET tube)

Question 29

How can you manage feline asthma using inhalers + management?

Answer 29

• Salbutamol - 1 puff as required - lasts 4 hrs
• Fluticasone - 2 puffs a day - takes 10-14days for peak effect
• Keep away from environmental allergens
• Bronchodilators - terbutaline
• Prednisolone

Question 30

What is seen with bronchial foreign bodies?

Answer 30

• Sudden onset coughing
• Usually gun dog breeds (scenting / sniffing)
• History of exercise through fields / arable crops / woodland
• If long standing, halitosis often marked
• Partial response to antibiotics

Question 31

What are other causes of coughing?

Answer 31

• Bronchial / Pulmonary neoplasia
• Lung parenchymal disease (typically ineffective cough
• Angiostrongylus vasorum infestation
• Cardiac disease in the dog – MVD, DCM