A few common causes of respiratory system conditions are asthma, bronchitis, cat flu, hair balls, heartworms, heatstroke, and kennel cough. Learn more about these common conditions now.

Asthma
Vets still are not sure what causes asthma, but it appears to be due to an allergic reaction to such things as pollen, litter-box dust, or even perfume that causes airways to get inflamed and swollen, reducing the flow of oxygen to the lungs. Dogs occasionally get asthma, but it is much more common in cats.

Asthma in cats is so common, in fact, that it is sometimes called feline allergic bronchitis, or simply, cat asthma. There are two forms of this condition. In cats with acute asthma, the attacks come on suddenly, causing loud wheezing. In addition, your cat may sit with his shoulders hunched -- or lie down with his mouth open -- straining to breathe.

"When your cat has an acute asthma attack, he needs emergency medical attention," says Lynne Boggs, D.V.M., a veterinarian in private practice in Austin, Texas.

The other form of cat asthma, called chronic asthma, is a lot less serious, at least in the short run, says Dr. Boggs. Your cat will breathe more rapidly and deeply than usual, but he won't be starved for air. The problem is that chronic asthma increases pressure inside the lungs, which can put pressure on the heart, causing additional problems.

There is no cure for asthma. If your pet has had one attack, he will probably have another. Veterinarians usually treat asthma with medications to open airways inside the lungs, along with anti-inflammatory drugs to reduce the swelling.

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Bronchitis
Your pet's airways are lined with tiny, hairlike projections called cilia. Like little soldiers, cilia protect the lungs by trapping bacteria, viruses, and other irritants before they do harm. Sometimes, however, the cilia don't work as efficiently as they should, allowing harmful irritants to get inside. As a result, the bronchial tubes (tiny airways inside the lungs) may get inflamed and swollen, a condition called bronchitis.

Pets with bronchitis often have a dry, hacking cough, which may be accompanied by gagging. Bronchitis usually isn't serious, but it can make pets feel tired and run-down. It is important to encourage them to get plenty of rest. It is also helpful to turn on the humidifier because moisture in the air will help soothe irritated lungs.