CONDITION

Feline Asthma

Feline asthma is a condition in which the airways in the lungs become inflamed and narrowed in response to triggers that would not normally cause trouble. This narrowing makes it harder for air to move in and out, and often leads to coughing, wheezing, or episodes of laboured breathing that can look sudden and alarming. Owners often notice a persistent cough, sometimes described as a hacking or retching sound, or they may see their cat breathing with visible effort, an open mouth, or a crouched posture. These signs can appear out of nowhere or build gradually, and it is not always obvious at first whether what you are seeing is something in the airway, the heart, or somewhere else in the chest. This page explores what feline asthma may look like in day-to-day life, what is happening in the airways when it occurs, how it is distinguished from other causes of coughing or breathing difficulty, and the range of approaches used to manage it over time.

Why this matters now

Feline asthma can appear at any age, though signs often first become noticeable in cats between one and eight years old. Siamese and Himalayan cats may develop the condition more frequently than other breeds. Environmental factors such as cigarette smoke, dusty litter, aerosol sprays, pollen, and household cleaning products can trigger or worsen airway inflammation in susceptible cats.

The condition typically follows a relapsing-remitting pattern, with periods of relatively normal breathing interspersed with episodes of respiratory difficulty. Some cats experience mild, infrequent episodes that remain stable for years, while others develop more frequent or severe attacks over time. A minority of cats progress to persistent airway remodelling, in which the structure of the airways changes and breathing difficulty becomes more constant.

Signals & patterns

Early signals

Intermittent dry cough

A cat may cough sporadically, often with a hacking sound that can be mistaken for an attempt to bring up a hairball. The cough tends to be dry rather than wet, and may occur more often after activity or excitement.

Increased breathing effort at rest

The chest and abdomen may move more visibly during breathing, or the cat may breathe with an open mouth after mild exertion. These changes reflect the extra work required to move air through narrowed airways.

Wheeze or whistle on breathing

A soft whistling or wheezing sound may be audible when the cat exhales, particularly in a quiet room. This noise arises from air passing through constricted or inflamed airways.

Reduced tolerance for play

A cat may stop playing sooner than usual, or choose to rest more often between bursts of activity. This quieter behaviour can reflect the discomfort or effort associated with breathing through inflamed airways.

Later signals

Breathing with neck extended

During more pronounced episodes, a cat may stretch the neck forward and lower the head, a posture that can help open the airway. The cat may remain still and avoid movement until breathing eases.

Blue-tinged gums or tongue

In severe episodes, the mucous membranes may take on a dusky or blue colour, reflecting reduced oxygen delivery. This sign indicates significant airway obstruction and is a marker of a more advanced or acute crisis.

Rapid, shallow breathing

The breathing rate may increase markedly, with shallow chest movements that suggest the cat is unable to take deep, effective breaths. This pattern often accompanies more frequent or prolonged episodes of airway constriction.

Click to read about the biological mechanisms

How this is usually investigated

Diagnosis typically begins with a detailed history focusing on the pattern, timing, and triggers of respiratory signs, alongside observation of the cat's breathing pattern and effort at rest. Physical examination may reveal increased respiratory rate, prolonged expiratory phase, or wheeze audible through a stethoscope, though some cats appear entirely normal between episodes. Because the clinical picture can overlap with other causes of coughing and respiratory difficulty — particularly chronic bronchitis, heart disease, and lungworm infection — targeted tests are used to narrow the differential picture and assess the degree of airway inflammation.

Radiography

Purpose: Thoracic radiographs allow visualisation of the lung fields, airways, and cardiac silhouette to identify patterns consistent with airway disease — such as bronchial wall thickening, increased bronchial markings, or hyperinflation — and to exclude other structural causes of coughing such as heart enlargement, pulmonary masses, or evidence of lungworm-associated changes.
Considerations: Many asthmatic cats have radiographs that appear entirely normal, particularly early in the disease or between episodes, so a normal study does not exclude the diagnosis. The changes seen can also overlap with chronic bronchitis, making radiography more useful for ruling out other conditions than for confirming asthma specifically.

Bronchoalveolar lavage (BAL)

Purpose: A sterile saline flush is introduced into the lower airways and retrieved, allowing cytological analysis of the cellular population within the bronchi. An increased proportion of eosinophils is consistent with asthma, while neutrophils may suggest bacterial bronchitis or another inflammatory process.
Considerations: The procedure requires general anaesthesia and carries a small risk in cats with severe airway compromise. Eosinophilia can occasionally be seen in other conditions, including lungworm infection or eosinophilic bronchopneumopathy, so results are interpreted alongside the broader clinical picture.

Complete blood count

Purpose: A blood sample is analysed to assess circulating white cell populations. Some asthmatic cats show peripheral eosinophilia, which can support the suspicion of an allergic or parasitic process.
Considerations: Eosinophil counts are often normal in feline asthma, so a normal result does not exclude the condition. Eosinophilia is non-specific and may be seen with parasitic infection, certain gastrointestinal conditions, or hypereosinophilic syndromes, so it does not confirm asthma in isolation.

Faecal analysis

Purpose: Faecal samples are examined for lungworm larvae, particularly Aelurostrongylus abstrusus, which can cause coughing and respiratory signs that closely mimic asthma in outdoor or hunting cats. This parasite is uncommon in Great Britain compared with continental Europe, so it is a lower-probability differential for most UK cats, though still worth ruling out when clinical suspicion is high or there is a travel or import history.
Considerations: Larval shedding can be intermittent, so repeated samples or specialised concentration techniques may be needed to detect infection. A negative result does not definitively exclude lungworm, particularly if clinical suspicion is high based on lifestyle and environment.

Echocardiography

Purpose: Ultrasound imaging of the heart is used to assess chamber size, wall thickness, and function, allowing differentiation between respiratory signs caused by airway disease and those caused by cardiac pathology such as hypertrophic cardiomyopathy.
Considerations: Not every coughing cat requires echocardiography, but it becomes particularly useful when a heart murmur, gallop rhythm, or cardiac enlargement is detected on physical examination or radiography, or when the clinical response to asthma treatment is unexpectedly poor.

Options & trade-offs

Management of feline asthma typically combines environmental modification, anti-inflammatory medication, and bronchodilator therapy, with the balance between these elements tailored to the individual cat's pattern of disease and the household's practical constraints. Some cats remain stable with minimal intervention, while others require sustained medication to prevent progressive airway remodelling. Different owners find different combinations workable depending on the cat's temperament, the predictability of episodes, and the feasibility of long-term treatment at home.

Environmental allergen reduction

This involves identifying and minimising exposure to potential airway irritants within the household, such as dusty litter substrates, aerosol sprays, cigarette smoke, scented candles, or air fresheners. Switching to low-dust, unscented litter, improving ventilation, and using air filtration can reduce the frequency and severity of episodes in some cats. For cats with seasonal patterns, allergen exposure may vary with pollen levels or changes in heating and ventilation practices.

Trade-offs: Environmental control can be difficult to achieve comprehensively, particularly in multi-cat or multi-person households, and the specific triggers for an individual cat are often unclear. Some cats continue to experience episodes despite rigorous environmental management, indicating that allergen exposure is only part of the picture.

Inhaled corticosteroids

Inhaled glucocorticoids, delivered via a spacer device designed for cats, allow direct deposition of anti-inflammatory medication into the airways with minimal systemic absorption. This approach targets the underlying eosinophilic inflammation and, when used consistently, can reduce airway remodelling and the frequency of acute exacerbations. Commonly used preparations include fluticasone.

Trade-offs: Inhaled therapy requires the cat to tolerate a mask and spacer device, which some cats find distressing despite gradual habituation. The cost of the delivery system and ongoing medication can be substantial, and inhaled therapy is less effective during acute episodes when airway obstruction limits deposition, so rescue medication may still be needed.

Oral corticosteroids

Systemic glucocorticoids such as prednisolone are used to suppress airway inflammation, either as daily maintenance therapy or during acute flare-ups. Oral administration is straightforward in most cats and provides reliable systemic anti-inflammatory effect, which can rapidly reduce bronchial oedema and mucus production.

Trade-offs: Long-term oral corticosteroid use carries a risk of systemic side effects, including polydipsia, polyuria, weight gain, muscle wasting, and an increased susceptibility to diabetes mellitus, particularly in cats. The threshold for these effects varies between individuals, and some cats require ongoing monitoring of glucose and body condition.

Bronchodilator therapy

Beta-2 agonists such as terbutaline or salbutamol relax bronchial smooth muscle and provide rapid relief from bronchoconstriction during acute episodes. They can be administered orally, by injection, or by inhalation, and are particularly useful as rescue medication when a cat is experiencing laboured breathing or wheeze.

Trade-offs: Bronchodilators address the mechanical narrowing of the airways but do not modify the underlying inflammation, so they are typically used alongside anti-inflammatory therapy rather than as sole treatment. Some cats experience transient tachycardia or restlessness, and overreliance on bronchodilators without controlling inflammation may allow progressive airway damage.

Leukotriene receptor antagonists

Medications such as montelukast block the action of leukotrienes, inflammatory mediators involved in bronchoconstriction and mucus production. Zafirlukast, once an alternative, has been unavailable in the UK since 2018. They are sometimes used as adjunctive therapy in cats whose asthma is incompletely controlled by corticosteroids alone, or as a steroid-sparing strategy in cases where systemic side effects are a concern.

Trade-offs: The evidence base for leukotriene antagonists in cats is smaller than for corticosteroids, and individual response is variable. They are generally well tolerated but add to the complexity and cost of the management plan, and their role is typically supplementary rather than foundational.

Common misconceptions

Misconception:

"Coughing in cats is a sign of a hairball problem."

Reality:

While cats do occasionally vomit hair, true coughing — a forceful expulsion of air from the lungs — is often mistaken by owners for retching or gagging. A cat crouched low with neck extended, producing a dry, hacking sound without bringing up material, is more likely to be coughing due to airway disease rather than attempting to clear a hairball. Chronic coughing warrants investigation of the respiratory system.

Misconception:

"Asthma only affects cats that go outdoors."

Reality:

Feline asthma is fundamentally an allergic airway disease, and many of the most common triggers — such as house dust mites, mould spores, scented products, and cigarette smoke — are found indoors. Indoor-only cats can develop asthma, and in some cases the concentration of allergens in a poorly ventilated indoor environment may be higher than outdoors. Lifestyle is one factor among many, but it does not determine susceptibility.

Misconception:

"If the medication works, the cat is cured and can stop treatment."

Reality:

Feline asthma is a chronic, manageable condition rather than a curable one. When signs improve or resolve with treatment, it typically reflects effective control of inflammation and bronchoconstriction, not elimination of the underlying immune reactivity. Discontinuing medication often leads to recurrence of signs and may allow progressive airway remodelling to resume, so long-term or intermittent treatment is usually needed to maintain stability.

Related conditions

Pneumonia

Pneumonia can occur as a complication in cats with feline asthma, particularly when chronic airway inflammation impairs normal clearance mechanisms or when aspiration occurs during severe respiratory episodes. Both conditions involve respiratory distress, though pneumonia typically presents with systemic signs of infection alongside breathing difficulty.

Hypertrophic Cardiomyopathy in Cats

Hypertrophic cardiomyopathy may present with breathing difficulty, coughing, or respiratory distress that can resemble feline asthma, particularly when heart disease leads to fluid accumulation affecting the lungs. Distinguishing between cardiac and airway causes of respiratory signs often requires diagnostic imaging.

Atopic Dermatitis in Dogs

Atopic dermatitis and feline asthma both reflect allergic immune hypersensitivity, with environmental allergens triggering inflammation in different target tissues—skin in atopic dermatitis and airways in asthma. Cats with one atopic condition may be predisposed to developing other manifestations of allergic disease.

Feline Idiopathic Cystitis

Feline idiopathic cystitis and feline asthma can both be influenced by stress and involve inflammatory responses without clear infectious triggers. In some cases, environmental or emotional stressors may contribute to flare-ups of either condition, though they affect entirely different organ systems.

Feline Herpesvirus (FHV-1)

Feline herpesvirus infection can cause chronic respiratory signs including coughing and wheezing that may be mistaken for feline asthma, particularly in cats with lingering airway inflammation following acute infection. Persistent viral damage to respiratory tissues may also predispose some cats to secondary airway hypersensitivity.

Patterns of coughing, breathing effort, and response to environmental change become clearer over time, and keeping a loose record of episode frequency and context can be useful in conversations about adjusting management. Cats with asthma may also be predisposed to other immune-mediated or inflammatory conditions, and understanding how the respiratory system interacts with the broader immune landscape may provide perspective on the individual cat's health over the longer term. If episodes are becoming more frequent despite treatment, or if new signs such as lethargy or reduced appetite appear, those shifts in pattern are worth noting.

Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS