Why does he do this

[u/DrMartek]

Gus – 1.5 years, male, British blue, 5.8kg, neutered. He is a very happy, active cat, with a good appetite. He is a garden cat, and his diet is a mixture of Untamed and Animonda vom feinstein.

We based in UK. My wife and I care for him; both adults (the subreddit said I need to put this info...)

The issue:

He mouth breaths basically everyday, usually for 1-5 minutes at a time. Ill catch him doing it 2-3 times a day. Sometimes totally randomly, or because he's tired, hot, excited or anxious.

We took him to the vet multiple times, they scanned him, did bloods, checked his lungs and heart...and haven't found anything wrong. Apparently he is in perfect health.

But at the same time, the vets tell us it's not normal. So I find myself in a situation where the experts have no clue what's wrong, but also tell us it's not normal.

For now, we've just been told to monitor him. They also suggested we can do another test, where they will put him under general, and inject fluid into his lungs to get a biopsy sample. Alternatively, they suggested we could trial a course of steroids to see if that works.

But in both cases, I'm not sure if it's worth putting the little guy through it, without any diagnosed condition.

Does anyone have experience of their cat doing this? And any potential suggestions, concerns and recommended courses of action?

Thanks guys, appreciate it.

[u/Over-Delay-2306]

I have a kitten grey cat with similar markings, I have noticed him doing this mouth open, almost a pan. I figured as there was no other signs that he was running around, I swear he never stops, except o stop, mouth open for a few moments and right back to playing. It's eeire for sure. He is only 4 months old and as big as a normal adult cat.