Feline Asthma

Question 1

What is a classic sign of feline asthma? What else is seen?

Answer 1

expiratory dyspnea –> expiratory push

wheezing and coughing, exercise intolerance

Question 2

What are 3 possible triggers of asthma? What do they result in?

Answer 2

1. damage, hypertrophy, and/or metaplasia of airway epithelium
2. increased mucous production by goblet cells
3. hypertrophy and spasm of bronchial smooth muscle

inflammatory cell infiltration into bronchial mucosa and submucosa –> mucous accumulation and airflow reduction

Question 3

What are the 3 causes of airflow reduction in cases of feline asthma?

Answer 3

1. airway edema
2. airway narrowing from cellular infiltrates
3. airway smooth muscle constriction

Question 4

Why are dramatic clinical signs seen with relatively mild airway constriction?

Answer 4

• 50% reduction in diameter = 16x reduction in airflow
• stimulation of cough mechanoreceptors by inflammatory infiltrate

Question 5

Feline asthma is a diagnosis of exclusion? What are some major rule outs?

Answer 5

• heart disease
• pneumonia
• pneumothorax
• pleural effusion
• pulmonary neoplasia
• inhaled FB
• respiratory parasites

Question 6

What are the 2 diagnostic tests of choice for feline asthma?

Answer 6

1. CBC
2. thoracic radiographs - bronchial pattern = train tracts and doughnuts = thickened bronchial walls

Question 7

What treatment is recommended for cats with intermittent signs of asthma?

Answer 7

inhalant bronchodilator (Albuterol) as needed

• assumption is that chronic inflammation requiring daily anti-inflammatories is not present

Question 8

What treatment is recommended for cats with consistent signs of asthma?

Answer 8

long-term corticosteroids –> high-dose (1-2 mg/kg PO BID for 10-14 days, them taper)

• once a response is seen, begin inhaled steroids as oral steroids are being tapered

Question 9

How should cats with emergency presentation in acute respiratory distress due to asthma be treated?

Answer 9

• administer oxygen
• bronchodilator
• sedation

Question 10

What inhaled medications can be administered to cats with asthma? What are some challenges to this way of administration?

Answer 10

fluticasone (lack systemic side effects associated with other steroids) + albuterol

• requires a spacer (ie Aerocat)
• difficult to get cats to inhale deeply on comand