Feline asthma: symptoms, diagnosis and treatment with inhalers
Feline asthma is a chronic inflammation of the airways that is mistaken for hairballs for years. It cannot be cured, but it can be very well controlled, and many asthmatic cats live long, normal lives. The keys are getting the diagnosis right, reducing what triggers it at home and learning to use an inhaler spacer.
What asthma is in a cat
In asthma, the lower airways overreact to substances the cat breathes in. The bronchi become inflamed, produce mucus and narrow, and air passes with difficulty, especially when breathing out. It is a disease similar to asthma in people and, as with them, it is thought to have an allergic basis. It is distinguished from chronic bronchitis, in which the inflammation is similar but without that allergic component; in practice, both are managed in much the same way. It usually appears in young or middle-aged cats, and has been described more often in the Siamese and other Oriental breeds, although any cat can have it.
How to recognise it
The most common symptom is coughing: the cat crouches, presses its body to the floor, stretches its neck and gives several dry expulsions of air, without anything coming up. Many owners believe for years that it is hairballs. There may also be wheezing, faster or more laboured breathing, exercise intolerance (it stops playing sooner) and, during an attack, open-mouth breathing. Between episodes, most asthmatic cats are completely normal. Film any episode of coughing or odd breathing: it is one of the most useful pieces of evidence for the vet, because it is almost never seen in the consulting room.
What triggers it at home
Airborne irritants are the factor you can control most. Tobacco smoke is the clearest, including the residue left on clothes or the sofa. So are scented candles, incense, spray or plug-in air fresheners, essential oil diffusers, spray cleaning products, hairspray and perfumes. Dust from some litters, especially very fine clay ones, can make it worse. Pollens, house dust mites and mould are possible allergens. Stress and sudden changes in temperature can bring on an attack. The trigger is not always identified, but reducing all of the above helps almost every asthmatic cat.
An attack: what to do
If your cat is breathing with its mouth open, its belly is moving a lot as it breathes, its gums look bluish or it cannot stop coughing, it is an emergency: go to the vet or an emergency hospital immediately, calling ahead to say you are coming. Put it in the carrier with minimal handling and keep things cool and calm. If your cat already has a diagnosis and the vet has given you a rescue inhaler with instructions for attacks, use it as you were told and still go to the clinic if it does not improve within a few minutes. At the clinic it will be given oxygen, a bronchodilator and fast-acting corticosteroids, usually with a very good response.
How it is diagnosed
No single test confirms asthma; the diagnosis is made by adding up clues and ruling out other causes. Chest X-rays usually show a characteristic bronchial pattern, although they can be normal. Ruling out lungworm is essential, especially Aelurostrongylus abstrusus, which causes an almost identical cough and X-ray picture: this is done with specific faecal tests or, often, a trial parasite treatment. In areas with heartworm, that test is done too. The most complete test is a bronchoalveolar lavage under anaesthetic, which collects cells from the airways: in asthma, eosinophils usually predominate. Blood tests rule out other diseases.
Treatment: corticosteroids and bronchodilators
The basis of treatment is corticosteroids, which reduce inflammation in the airways. At first they are usually given by mouth for a few weeks to bring the inflammation under control, and then many cats move on to inhaled corticosteroids, which act directly in the airways with far fewer side effects elsewhere in the body. Bronchodilators open the airways during attacks, and some vets prescribe one to keep at home as a rescue treatment. Treatment is lifelong in most cats, although over time, and with control of the environment, the medication can often be reduced. Doses are always set by the vet and must not be changed on your own.
How to use the inhaler spacer
Cats cannot inhale on demand, so a spacer chamber with a mask shaped for a cat’s face is used. The inhaler goes at one end, the mask over the cat’s mouth and nose, the inhaler is pressed once and the cat is left to breathe normally inside the mask for the number of breaths the vet has told you, often around seven to ten. Almost every cat accepts it if introduced gradually: first leave the spacer where it can see it, then touch its face with the mask and give a treat, then hold it there for a few seconds without medication, and so on until you use it for real. A few days of training with treats turns it into a routine.
What it costs in Spain in 2026
As a guide: consultation, €40 to €60; chest X-rays, €60 to €150; faecal test for lungworm, €25 to €60; blood tests, €80 to €160; bronchoalveolar lavage with anaesthetic and laboratory work, €250 to €600. An inhaler spacer for cats, €40 to €80, bought once. Inhaled medication costs €20 to €60 a month depending on the product and dose. An attack treated at an emergency clinic with oxygen and medication, €150 to €400, and somewhat more if the cat is admitted. Follow-up check-ups, once or twice a year, €40 to €150 depending on the tests.
What not to do
Do not stop treatment because the cat is well: it is well because of the treatment. Do not use inhalers or medication meant for people or another animal on your own initiative: only those the vet prescribes, at the dose set for your cat. Do not smoke indoors or on the balcony with the cat nearby. Do not use air fresheners, incense or essential oils, which besides worsening asthma can be toxic to cats. Do not wet the cat or give it steam to help it breathe. And do not start leftover corticosteroids for a new cough without a diagnosis, because if the cause is a parasite or an infection you can make it worse.
Outlook and daily life
Most asthmatic cats that are properly diagnosed and treated have a normal, long life. There may be worse spells, in spring or with changes at home, and the vet can adjust treatment at those times. Keep a record of coughing episodes and of its resting breathing rate, because that is the best way to know whether control is good. Clean air, dust-free and unscented litter, a healthy weight (obesity worsens any respiratory problem) and less stress. With that, many cats go months or years without a single attack.
An asthmatic cat’s cough looks like a hairball that never comes up. It is diagnosed after ruling out lungworm and controlled with corticosteroids, often inhaled through a spacer, and clean air at home. Open-mouth breathing is an emergency.
Educational content from Michipedia, translated from the Spanish original. It does not replace the advice of a vet or a feline behaviour specialist. Every cat is an individual.