I just read the question for today about the girl with the older small dog that starts coughing when he is playing. I have a 3 year old female cat that actually does the same. As soon as I get her running around chasing a toy she has to stop and starts hacking like she is going to cough up a hairball but doesn’t. She is a bit overweight if that matters but the coughing doesn’t last long. What could be the cause of this in cats?
Based on your description I am most suspicious of feline asthma (known more formally as feline bronchitis). Feline asthma, like human asthma, causes constriction and irritation of air passages in the lungs. Mild cases cause intermittent coughing, and the coughing may be most pronounced when the cat is active. Some mild cases do not require treatment. However, severe cases can cause serious respiratory crises which may be life threatening, so it is important to take X-rays of the chest in order to assess the severity of the irritation in the lungs.
Be aware that asthma is not a foregone conclusion. Heart problems, infections in the lungs, heartworm or parasitic lung disease, and airway or pharyngeal (throat) irritation also may cause coughing. Any syndrome that causes coughing generally will cause more prominent symptoms during activity. Excess body weight also generally will exacerbate any syndrome that causes coughing.
A veterinary checkup is in order for your girl. An exam, chest X-rays, and some blood tests likely will yield a great deal of insight into this matter.
Photo: a nice picture of a cat. Not from a kitten mill. No known history of asthma. Just a nice picture of a cat.