About: Asthma is a respiratory condition which occurs when the muscles of the airways tighten and become inflamed in response to a trigger. This makes it hard for your cat to breathe air into the lungs.
Causes: Inhaling a substance which triggers an immune response. Common allergens include dust, pollen, perfume, smoke, mould and household chemicals, sprays and dust from cat litter.
Symptoms:Difficulty breathing, dry hacking cough, wheezing, rapid open-mouthed breathing, sitting with the head extended.
Diagnosis:Medical history and complete physical examination including listening to the lungs. Chest xrays, tracheal wash, fecal flotation and baseline tests to evaluate the overall health of your cat and look for signs of infection.
Treatment:Bronchodilators to open the airways and steroids to reduce inflammation. Long-term care includes avoiding the allergen if known.
What is feline asthma?
Also known as feline bronchial disease, allergic bronchitis, allergic airway disease and allergic asthma), asthma is a noninfectious respiratory condition that is characterised by acute constriction of the lower airways, which results in coughing and respiratory distress. Asthma is one of the most common causes of respiratory diseases in cats, affecting around one in 100, attacks may range from mild to severe and life-threatening.
Inhalation of an allergen is the trigger of asthma with common allergens such as pollen, perfume, cigarette smoke, smoke from household fires, mould, household sprays (hairspray, air fresheners etc.) and dust from cat litter. Over-representation of Siamese cats suggests a genetic predisposition, however, cats of all ages and breed can be asthmatic. Obese cats are also at greater risk of developing asthma.
What happens during an asthma attack?
The smooth muscles around the airways tighten and block the airflow.
The walls of the airways swell and become narrower, blocking the airflow.
The airways produce extra mucus, causing even more narrowing.
Contraction and narrowing of the airways which impede airflow into the lungs.
Sitting with the shoulders hunched over, neck extended with rapid open mouthed inhalations and exhalations (tachypnea)
Symptoms may be mild or severe, mildly affected cats they may cough or wheeze occasionally while severely affected cats may cough and wheeze daily, leading to airway constriction and open-mouthed breathing/panting. A severe asthma attack is a medical emergency which can lead to death.
There are other medical conditions with similar symptoms to asthma, so your vet may want to rule out heartworm, pneumonia, Bordetella and congestive heart failure.
Your vet will do the following:
Listen to the cat’s chest and breathing.
Take a chest x-ray to look for signs of bronchial inflammation and enlarged lungs, flattened diaphragm and doughnuts.
Tracheal wash or airway lavage to check for the presence of eosinophils (a type of white blood cell) and infectious organisms.
Fecal flotation to diagnose parasitic worm eggs, which can be a common cause of coughing in cats.
Complete blood count to check for infection and the presence of eosinophils.
Management of asthma as there is no cure, this may include:
Oral glucocorticoids – Reduce inflammation with oral glucocorticoids. There may be side effects from long-term use of steroids such as diabetes, pancreatitis, increased urination, weight gain, behavioural changes. Cats start on oral steroids until the condition is stable. Medication will then be reduced until your cat is switched to inhaled steroids.
Inhalant glucocorticoids. Same as above, they reduce inflammation. There is a relatively new inhaler system on the market called AeroKat, Flovent is the most commonly used inhalant steroid. As inhaled steroids don’t get into the system as much as oral steroids, reducing side effects. Administer by placing a mask over your cat’s mouth and nose, the advantages are that the medication targets the airways directly.
Bronchodilators: These help open the airway at times of severe coughing or wheezing, the most common bronchodilator is albuterol (Proventil®, Volmax®, Ventolin®).
In an emergency, get your cat to the closest vet immediately as you will not be able to treat this at home. Your veterinarian will usually inject a corticosteroid to reduce inflammation and use a bronchodilator to help open the airway. A life-threatening asthma attack will require administration of ephedrine.
Reduce exposure by removing common triggers in the environment, this includes avoiding using scented products and airborne particles such as dust, smoking outside, switching to a dust free type of cat litter (silicone and paper pellets are low in dust).
Air purifiers and humidifiers can also reduce the number of attacks as dry air is a trigger.
Weight loss for overweight cats, overseen by a veterinarian as sudden weight loss can cause feline hepatic lipidosis.