What could those be symptoms of? The cat has recently started to get Cisapride (Propulsid) for megacolon. There was some coughing a time ago, but at a recent checkup the vet said that there wasn't anything strange in the cat's breathing or heart.

What could those be symptoms of? The cat has recently started to get Cisapride (Propulsid) for megacolon. There was some coughing a time ago, but at a recent checkup the vet said that there wasn't anything strange in the cat's breathing or heart.
Sevenseas, I'm worried my cat has megacolon too. Too many vistis to the animal emergency clinic to give him enemas for impacted bowels, and he has been pooping outside the litterbox for a while now. I have to take him in this week to get checked out at the vet, but maybe sounds like this is a side effect of his meds? So far the past few months I've just been giving him daily a stool softener/hairball remedy formula, he now eliminates pretty regularly, but not where he should:-/ Maybe you should see if mouth open and drowsy is a side effect of your cat's medicine, if so, they may switch to another one?

There are a lot of heart problems that you can't hear with a stethascope. You can usually do an EKG in office pretty cheap. We used to run them for $75 and you'd have the results back in about a day (we did it over the phone). The cat just has to sit there with clips on its legs for a few minutes. Open mouth breathing can be a sign of heart problems, asthma, stress, thyroid problems... have you had a full blood panel run recently?

Thanks for the responses Lilith and rabid_child.

The vet found out a tonsil infection and possible bronchitis, so I guess the explanation is neither Propulsid side effects nor a heart problem (at least I hope so, we'll see what the proper medication will do).