, also known as feline bronchitis. It can affect cats of all ages, and about 1% of cats are diagnosed with this.
Typically, it is caused when inhaled particles (allergen) cause the airways to contract. Though it is difficult-to-impossible to pin it down to anything in particular, common allergens include pollen, smoke, sprays (hair spray, deodorant, etc.), and dust from the critter's cat litter.
The symptom a cat owner might notice would be a dry, hacking cough. In fact, it is common to confuse it with the cat trying to expel a hairball. We initially thought that with my cat, who was hacking around the time of her annual check-up. Over the following two weeks, she was given hairball medicine, but the coughing seemed to get worse. A severe case would eventually lead to panting and constriction of the airway, which is quite serious.
To diagnose this, a chest x-ray is taken, as well as blood work. Where air shows up black on the x-ray, an affected cat's airway will show prominently. The blood work will both show the allergen concentration in the cat's blood, as well as help rule out other problems (parasites, for example).
There is no cure for this. Some medications will help alleviate the symptoms. This include oral medications (in some cases, over the counter), as well as inhaled medication. The latter is thought to be more effective, but, in addition to the expense, it puts a great deal of stress on the cat. Not that the oral option is a picnic.
DISCLAIMER: This information is written for informational purposes only. The writer is not a veterinarian, and therefore cannot give medical advice. Please take your pet to see his or her veterinarian for diagnosis and treatment!