Lower airway disease in cats Flashcards
(55 cards)
What ages of cats does lower airway disease tend to affect?
- young adult to middle aged
- but can affect any age
Older cats with respiratory difficulty: increased suspicion for
- hyperthyroidism
- neoplasia
- cardiac disease
Clinical history for lower airway disease
usually a low grade chronic disease: coughing, audible wheezing, ‘exercise intolerance’.
sometimes a very acute presentation: brought in as an emergency, respiratory distress, mouth breathing, tachypnoea.
episodic respiratory distress: self-limiting? respiratory effort?
Younger cats and kittens with respiratory difficulty: increased suspicion for
infectious disease, e.g. viral, parasitic, mycoplasma, bacterial, toxoplasma
Is bacterial pneumonia common or uncommon compared to dogs?
- Relatively uncommon
History questions to ask
are there any trigger factors (environment change, new cat litter, passive smoking, seasonal)? is the cough productive? is anything ‘brought up’? (often confused with hair balls) any significant weight loss or anorexia? <- these animals don’t usually go off their food or lose weight so consider other differentials
Why is it important to auscultate the heart for a cat in respiratory distress?
Heart failure is the most common cause of resp distress in cats, so need to rule it out
Assessing the cat
initial assessment should be hands off.
sympathetic stimulation is counterproductive - bring them to a quiet, calm place
Physical exam
- resp pattern (watch & listen, try to localise disease)
- can be deceptively normal
- auscultation: listen for an expiratory wheeze, is the heart normal (murmur, gallop sounds, tachycardia/bradycardia)
resp pattern for lower airway disease
- often more subtle
- laboured expiration, prolonged expiratory phase, additional expiratory push, audible expiratory wheeze
- increased airway resistance due to bronchospasm, mucus, bronchial wall thickening
- occasional paroxysmal coughing
What things do you need to look out for in the clinical history for a pt with URT disease?
dysphagia +/- salivation, coughing/gagging (may be triggered by eating/drinking), heat shaking behaviour (may indicate nasal disease)
Resp pattern for laryngeal/URT disease
laboured inspiration, stridor, increased inspiratory effort, slow inspiratory phase.
+/- change in purr or vocalisation
Signs of feline asthma
- episodic respiratory distress and dyspnoea, coughing
Is feline asthma reversible?
- yes
What of DAMNIT-V is most likely to cause airway disease in cats?
Inflammatory - immune-mediated? infectious?
Signs of chronic bronchitis
- coughing is a key feature
Airway diseases in cats - examples
- feline asthma
- chronic bronchitis
Causes of feline asthma (/aetiology of it)
Inhaled allergen -> airway hyper reactivity -> bronchoconstriction.
eosinophilic and neutrophilic airway inflammation
Aetiology of chronic bronchitis
response to infection or inhaled irritants -> airway damage -> excess mucus -> thickening of the airway walls.
neutrophilic airway inflammation?
Is chronic bronchitis reversible?
No
Pathogenesis of chronic bronchitis & feline asthma
hyper-reactivity of the bronchial smooth muscle, acute bronchoconstriction in response to a trigger factor, inflammation of bronchial mucosal lining (histamine and leukotriene release), overproduction of mucus.
airway obstruction occurs due to: bronchoconstriction, inflammation and mucus plugs in narrowed bronchioles.
air trapping causes destruction of bronchioles.
end result is chronic damage
What can cause hyper-reactivity of the bronchial smooth muscle?
- type I hypersensitivity, autonomic imbalance, mucociliary imbalance
Differential diagnosis for coughing
URT disease, inflammatory lower airway disease, infectious (bacterial, viral, parasitic), FB, neoplasia, (heart disease rarely causes coughing in cats)
Differential diagnosis for hyperpnoea/tachypnoea/dyspnoea: CRS
pleural space disease: mediastinal disease, ruptured diaphragm, PPDH, cardiac failure.
lung disease: airways, lung parenchyma, cardiac failure
