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 an owner is 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, and it is most often diagnosed in young to middle-aged adult cats. Siamese cats have been suggested to be predisposed, although this has not been firmly established. 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. Separately from this slow course, an acute attack can narrow the airways severely within minutes. A cat in this state may breathe with its mouth open, with the belly pumping on each breath, or with grey or blue gums, and this degree of airway narrowing can become fatal if it is not relieved, sometimes within hours. Stress makes breathing difficulty worse, so keeping a struggling cat calm and handled as little as possible on the way to treatment can reduce the strain on its breathing. Cats also tend to hide breathing difficulty until it is well advanced, so an episode that looks brief may reflect more compromise than it appears to.
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.
Rising sleeping breathing rate
The number of breaths a cat takes while asleep may creep up over days or weeks. Counting breaths while the cat sleeps gives an objective record that can be compared over time. A rising count can reflect narrowed airways, but heart disease can raise it too, and the count alone cannot show which. Breathing that can be seen taking effort, rather than simply a higher count, is not an early sign and is described with the later signals.
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. A cat that holds this posture to breathe while resting is showing visible breathing effort at rest, described below, which carries the same weight.
Blue-tinged gums or tongue
In severe episodes, the mucous membranes may take on a dusky or blue colour, reflecting reduced oxygen delivery. This is a late sign. By the time the gums look blue or grey, blood oxygen has already fallen a long way, and a cat in this state can deteriorate to collapse or death over minutes to hours. Pink gums are not reassurance, as many cats in serious breathing difficulty keep a normal gum colour until late.
Rapid, shallow breathing
The breathing rate may increase markedly, with shallow chest movements that suggest the cat is unable to take deep, effective breaths. Fast, shallow breathing at rest is the pattern more typical of fluid in or around the lungs than of asthma, where the effort falls mainly on breathing out. At home the two cannot be reliably told apart. It is a form of visible breathing effort at rest, described below, and can progress within hours.
Open-mouth breathing at rest
Healthy cats rarely breathe with the mouth open, apart from a brief spell after vigorous play, heat or stress that settles quickly once the cat is calm and resting. Open-mouth breathing at rest, or panting that does not settle, reflects marked difficulty moving air. It can accompany a severe asthma attack, heart failure or fluid around the lungs, and these look alike from outside.
Visible breathing effort at rest
In a healthy cat at rest, breathing is barely visible or audible. Chest and belly movements that can be seen working with each breath while the cat is resting or asleep show that moving air has become a struggle. This is not an early or mild sign, and its severity cannot be graded at home. Effort at rest can come from severe airway narrowing, heart failure or fluid around the lungs, which look alike from outside, and it can progress to open-mouth breathing, collapse or death within hours.
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
Bronchoalveolar lavage (BAL)
Complete blood count
Faecal analysis
Echocardiography
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 control airway inflammation, which may also help limit 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, may help limit airway remodelling and can reduce the frequency of acute exacerbations. Commonly used preparations include fluticasone, a human inhaler with no UK veterinary authorisation for cats, prescribed under the cascade.
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. The threshold for these effects varies between individuals, and some cats require ongoing monitoring of glucose and body condition. Corticosteroids have also been associated with the onset of congestive heart failure in cats with underlying heart disease, which matters because heart disease and asthma can look alike.
Bronchodilator therapy
Beta-2 agonists such as terbutaline or salbutamol relax bronchial smooth muscle and provide rapid relief from bronchoconstriction during acute episodes. Neither is authorised for cats in the UK. Both are human medicines prescribed under the cascade. Depending on the drug, they are given by inhaler through a spacer or by injection, 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. They are occasionally 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. Montelukast and zafirlukast are human medicines with no UK veterinary authorisation. Any use of montelukast in cats is under the cascade, and zafirlukast is no longer marketed in the UK.
Trade-offs: Evidence of benefit in cats is limited. In experimental feline asthma, leukotriene levels did not rise meaningfully after allergen challenge, and zafirlukast did not measurably reduce airway inflammation, unlike corticosteroids. 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 an add-on rather than a main treatment.
Common misconceptions
"Coughing in cats is a sign of a hairball problem."
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 from airway disease than trying to clear a hairball. A cough that keeps recurring points to the airways rather than to hair.
"Asthma only affects cats that go outdoors."
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.
"If the medication works, the cat is cured and can stop treatment."
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 and lower airway infection can cause coughing and increased breathing effort that resemble asthma. Fever, lethargy and reduced appetite point more towards infection, but the two often need radiographs and airway sampling to separate.
Hypertrophic Cardiomyopathy in Cats
Hypertrophic cardiomyopathy can cause rapid or open-mouth breathing when fluid builds up in or around the lungs, and this can look identical to a severe asthma attack at home. Telling the two apart needs imaging, and it matters because corticosteroids used for asthma have been associated with the onset of heart failure in cats with underlying heart disease.
Feline Herpesvirus (FHV-1)
Feline herpesvirus mainly affects the upper airway, causing sneezing, nasal and eye discharge and a snuffly, congested sound. Owners can confuse this noisy upper-airway breathing with the cough or wheeze of asthma, although the two affect different parts of the respiratory tract.
Pleural Effusion
Fluid around the lungs, from causes such as heart failure, infection, FIP or cancer, produces rapid, shallow or open-mouth breathing that can be mistaken for an asthma attack. It can only be told apart from asthma with imaging, and fluid compressing the lungs may need draining.
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. Changes fall into three groups that carry different weight. The first is a slow drift in cough frequency over weeks, which is a matter for planned review. The second is the sleeping breathing rate. A healthy cat asleep or resting calmly usually takes roughly 15 to 30 breaths a minute. A count that is consistently above about 30, or that keeps climbing from the cat's usual figure over days or weeks, is not a matter for planned review. Heart disease as well as asthma can raise the count, and a steady rise can be an early sign that heart failure is developing as fluid builds up in or around the lungs. The third group is any breathing that can be seen taking effort while the cat is at rest, fast shallow breathing at rest, open-mouth breathing, the belly pumping with each breath, grey or blue gums, a cat that crouches and will not settle, or a sleeping rate that rises over a day or less. These mark an attack that can become life-threatening within hours, and because cats tend to hide breathing difficulty, the degree of compromise is often greater than it looks. At home, a severe asthma attack cannot be reliably told apart from heart failure or fluid around the lungs. These look similar from outside, need imaging to separate, and are treated differently. 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: 9 October 2026 · Dr Alastair Greenway MRCVS