Feline asthma

Symptoms an owner can spot at home

• Coughing in a crouched posture with the neck extended and elbows out, often mistaken for hairball retching
• Wheezing, audible as a high whistle on exhalation
• Increased respiratory rate at rest, above roughly 30 breaths per minute while sleeping
• Open-mouth breathing after mild exertion
• Episodes that cluster seasonally or after cleaning, smoking, or litter changes

When to see a vet

• Open-mouth breathing, blue or grey gums, or breathing with the abdomen heaving, this is an emergency, go now
• Any resting respiratory rate consistently above 30 breaths per minute
• Repeated 'hairball' retching that never produces a hairball, that is a cough until proven otherwise
• A cough that worsens over days, or new lethargy and appetite loss
• Any cat already diagnosed with asthma needing rescue medication more often than usual

What it is

Feline asthma is a type-I hypersensitivity response in the lower airways: inhaled allergens trigger eosinophilic inflammation, smooth-muscle constriction, and mucus production. Air moves in more easily than it moves out, so cats trap air and, over time, remodel the airway wall. Reported prevalence is roughly 1 to 5% of cats, with young to middle-aged adults most commonly affected and Siamese cats over-represented in the literature.

The mislabelling problem is the practical issue. A coughing cat crouches low, extends the neck, and heaves, which looks close enough to hairball retching that owners often watch it for months. The distinguishing question is simple: does anything come up? Repeated retching that never produces hair or food is a cough, and a cough in a cat is never normal.

How vets diagnose it

Diagnosis is one of exclusion supported by imaging. Thoracic radiographs classically show a bronchial or bronchointerstitial pattern with hyperinflated lung fields and a flattened diaphragm, though a normal film does not rule the disease out. Airway sampling by bronchoalveolar lavage or tracheal wash showing eosinophilic inflammation gives the strongest support, and culture rules out infection.

• Heartworm-associated respiratory disease is the key mimic and should be screened in endemic areas; feline heartworm can present exactly as asthma.
• Lungworm (Aelurostrongylus) is excluded by faecal testing.
• Congestive heart failure is separated by echocardiography, since the treatment for one worsens the other.

Treatment overview

This is editorial overview, not a treatment plan; your vet builds the plan. Standard management pairs a corticosteroid to suppress airway inflammation with a bronchodilator for acute constriction. Delivery is increasingly by metered-dose inhaler through a feline spacer and mask, which concentrates drug at the airway and reduces systemic steroid exposure, an important consideration in cats already at risk of diabetes.

Cats accept inhaler therapy far more readily than owners expect, but only when it is introduced gradually with food-based conditioning rather than imposed on day one. Bronchodilators alone are never adequate maintenance; they relieve the spasm and leave the inflammation untouched.

What owners can do

• Switch to a low-dust, unscented litter. Litter aerosol is one of the most concentrated airborne exposures in a cat's day, and it is entirely under your control.
• Use a covered or high-sided litter box only if it does not trap dust; some cats do better with an open box in a ventilated location.
• Remove scented candles, plug-in air fresheners, aerosol sprays, and indoor smoking. Second-hand smoke is a documented airway irritant for cats.
• Run a HEPA air purifier in the room the cat sleeps in and vacuum with a HEPA filter.
• Count sleeping respiratory rate weekly, breaths per minute over 30 seconds, doubled. It is the single most useful home metric and it catches deterioration before a crisis.
• Keep weight down: excess body condition mechanically restricts chest expansion.
• Condition the inhaler and spacer with treats over a week before you need it in an emergency.