It is an upsetting sight to see a cat coughing. They crouch down on all four legs, extend their neck and often stick out part of their tongues and then make a horrible retching sound.

To the untrained eye, it appears they are having trouble breathing or even choking. I (Perry Jameson) am a veterinarian and it even bothers me to see one of my cats cough.

Most of us chalk these episodes up to a hair ball. We may try a hair ball diet or a paste with petroleum jelly to help them pass the hair. If this works, great; if not, your cat may have something more serious going on.

The most common more serious cause of a cough is asthma. Feline asthma is a common disease of the lower airways. Coughing is the most frequent symptom, but labored breathing also can be seen. In severe cases it can be fatal. Feline asthma is uncommon in kittens and rare to develop in older cats.

The cause is believed to be from an allergic reaction to something in the cat’s environment. Exposure to this allergen results in airway inflammation and mucus secretion resulting in coughing.

In severe episodes the airway may temporarily narrow (bronchoconstriction) resulting in acute respiratory distress. If the inflammation continues unchecked, the airways will remodel resulting in permanent changes.

Unfortunately there is no easy test to diagnose feline asthma. We start by getting information about the cat’s history and clinical signs. Cough (often confused by the parents as “hacking up a hairball”), wheeze and episodic respiratory distress are compatible with the diagnosis of asthma. Exercise intolerance is less frequently recognized because of the sedentary lifestyle of most cats. One difference with cats from other species is that they rarely cough with heart disease.

During our physical examination, we may find an easily elicited cough, wheezing (audible with or without a stethoscope) or increased respiratory rate and effort.

Chest X-rays are the next step. These can help eliminate other causes of respiratory distress. Results in asthmatic cats may range from normal to changes consistent with severe lower airway disease. Mucous may plug up the airways causing a lung lobe to collapse and this may also be noted on X-rays. These changes are not 100 percent specific for asthma as chronic bronchitis, lung worms and heartworm infections may cause similar changes.

My next step in obtaining the diagnosis is to perform a blood test for heart worm disease and a fecal test for lung worms. Sounds odd but lung worms are diagnosed by finding them in feces. The cat coughs up the worm eggs, swallows them and passes them in her feces where we can see them under the microscope.

The definitive test is bronchoalveolar lavage. Here, we sedate the cat and place a breathing tube into her trachea. A smaller tube is passed down the breathing tube through which saline can be flushed into the airways to “wash” some of the natural mucus out for collection. A pathologist can assess this to look for changes consistent with asthma or another disease. Even though bacterial infections are uncommon in cats, we always culture the fluid to rule this out.

Unfortunately, there is no cure for feline asthma at this time, so all we can do is try to treat the symptoms.

There are three major treatment recommendations for cats with asthma: steroids, bronchodilators and environmental modulation.

Steroids are the mainstay of therapy as they decrease inflammation. In emergency situations, they can be given by injection.

Once stable, most cats are sent home on oral steroids. The dose will gradually be tapered to the lowest affective amount. The problem with oral or injectable medications is they not only affect the lungs but every other part of the body. Cats tolerate them well but in a small percent, they can cause other problems. Once the inflammation is under control, they may be switched to inhaled steroids. These are much less likely to produce any undesired affects elsewhere in the body. However, I find the expense makes this hard for most families to afford.

Bronchodilators are important for the emergency treatment of asthma. They will open up the airways making it easier to breath. In the emergency setting or for severe episodes at home, they can be administered as an inhaler.

The best therapy of all would be to remove the allergen form the cat’s environment. This is often impossible as the allergen cannot be identified. It is more realistic to modify the environment so the cat has minimal contact with other stimuli that could trigger airway inflammation in a nonspecific manner, such as powders, dusts (kitty litter), aerosols and smoke. Hepa-type air filters may also prove beneficial.

Most cats with feline asthma will require lifelong steroid treatment to control disease and prevent permanent airway remodeling. With appropriate therapy at the lowest affective dosing, they will often do well.

Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to petdocs@postandcourier.com.