Respiratory tract diseases of SA 1 - The coughing dog and cat Flashcards
DDx - acute cough - 7
- Tracheobronchitis (KC) - Airway irritation - smoke, dust, chemicals, drugs - FB - Pulmonary haemorrhage - Acute pneumonia - Acute oedema - Airway trauma
DDx - chronic cough - 10
- Chronic bronchitis/bronchiectasis - Left sided heart disease (cardiomegaly –> compression) - Parasitic pneumonia - Tracheal collapse (mainstem bronchial collapse) - FB - Bronchopneumonia - Neoplasia - intrapulmonary or extralumenal - Eosinophilic diseases - dogs (eosinophilic bronchitis or pulmonary infiltrate with eosinophils), cats (FAD) - Pulmonary fibrosis - Ciliary dyskinesia
List parasites that can cause pneumonia in small animals - 3
Angiostrongylus vasorum (dogs) Filaroides (Oslerus) (dogs) Aelurostrongylus abstrusus (cats)
What should you assume if dogs have acute coughing that are otherwise well?
That the diagnosis is KC syndrome
What do you do in dogs with acute coughing that have signs not consistent with KC syndrome?
- Hx - PE - Thoracic radiographs (unlike cardiac patients where you always try to avoid anaesthesia)
Define ITB
Infectious TracheoBronchitis (i.e. Kennel cough, KC)
Define acute coughing
doesn’t persist for >2-3 weeks
Define chronic coughing
a cough that lasts > 3 weeks
Outline chronic bronchitis/bronchiectasis/chronic tracheobronchial syndrome
a syndrome characterised by chronic irritation to the bronchial mucosa –> increased mucous secretion, compromised respiratory defence mechanisms, coughing and bronchoconstriction. Increased mucous and bronchospasm –> airway narrowing –> compromised airflow. Also mucosal hyperplasia.
Does coughing itself cause damage?
Yes - repeated coughing cases repeated damage to the lower airways and perpetuates the inflammatory process.
Define PIE
Pulmonary infiltration with eosinophilia
Define FAAD
Feline allergic airway disease
Signalment chronic bronchitis/bronchiectasis/chronic tracheobronchial syndrome
any breed potentially. most commonly old small breed dogs (terriers), overweight too
Hx - chronic bronchitis/bronchiectasis/chronic tracheobronchial syndrome - 7
- good general condition - insidious onset - dry and hacking - unproductive - usually occurs in paroxysms - exacerbated by excitement/exercise - lead pulling often causes a bout of coughing (also cold temperature or humidity)
Clinical exam - chronic bronchitis/bronchiectasis/chronic tracheobronchial syndrome
- overweight (may) - harsh increased bronchial sounds - some wheezing - sinus arrhythmia (present or exaggerated) - cough often easily induced by tracheal palpation/pinch
Diagnosis - chronic bronchitis/bronchiectasis/chronic tracheobronchial syndrome - 5
BY EXCLUSION! - blood tests - usually normal - radiography - may show increased bronchial markings, false positives/negatives possible, may show bronchiectasis - Endoscopy - may confirm or rule out other causes - Tracheobronchial wash - mixed inflammatory cells and respiratory epithelial cells - Culture - often negative as secondary bacterial contaminants not always present
What are ‘doughnuts and tramlines’ on radiographs?
Indicates bronchiectasis: Tramlines - show the length of the bronchi Doughnuts - show the sectioned bronchi
Treatment - chronic bronchitis/bronchiectasis/chronic tracheobronchial syndrome
Education essential Unlikely to cure Patient management as important as drug therapy
Management recommendations - chronic bronchitis /bronchiectasis/chronic tracheobronchial syndrome - 5
- Clean atmosphere - Humidification of airway and coupage at home - Diet (especially if overweight) - Exercise regime - Avoid collars and choke chains - use ‘Halti type head collar instead
Drug therapy - chronic bronchitis/bronchiectasis/chronic tracheobronchial syndrome - 5
- BRONCHODILATORS (Theophylline, Terbutaline) - ANTIBACTERIALS (if bacterial infection is exacerbating signs) - EXPECTORANTS AND MUCOLYTICS - COUGH SUPPRESSANTS - ANTI-INFLAMMTORIES
How can you rule out a cardiac cause for a cough? 2
Presence of sinus arrhythmia and the absence of a murmur on auscultation.
What are the classes of bronchodilators?
XANTHINE agents - theophylline BETA-2 AGONISTS - terbutaline, adrenaline ANTI-MUSCARINICS - atropine
What are the classes of mucolytics?
Bromohexidine - useful in bronchial disease and bronchopneumonia to assist the expectoration of respiratory secretions
Define expectoration
the expel fluid from respiratory tract
What do anti-tussives do?
prevent/relieve a cough
Name 2 anti-tussives.
Butorphanol and codeine (both opiate derivatives)
When should you use anti-tussives? Contradindications?
To suppress a NON-productive cough. Helpful in cases of tracheal collapse and bronchial compression. Do not use to suppress a productive cough. Don’t use in patients showing radiographic alveolar pattern.
Why might anti-inflammatories be useful?
control cough due to inflammatory airway disease including chronic bronchitis + improved CS and QOL - too effective, animal/owner may become dependent on the drug, may lead to iatrogenic HAC, some disadvantages can be overcome with inhalation
Side effects - bronchodilators - 2
tachycardia and excitability
Expectorants - side effect
increase the productivity of cough
Side effect - corticosteroids
iatrogenic HAC
Side effects - cough suppressants - 2
trapping of airway secretions and sedation