Why is my cat barfing all the time?!

[Taranta]

We have a 12-ish year old female rescue moggie. Have had her for around 8-9 years, she's generally been in good health, sometimes vomits fur balls and grass and the like, but for the past few months has taken to vomiting practically every day, often in the middle of the night, early morning.
We took her to the vets, who ran a series of tests, all of which came back fine, and so vets suggested trying her on Royal Canin pet food, and said she might just be getting a bit vomitty in her dotage, as she is otherwise fine and lively. It's not made any difference though, so we're kind of at a loss as to what to do now?
Probably a daft suggestion, but It did occur to me to wonder of this was some kind of 'protest vomit' if cats do such a thing? We have a DS, 2 year old, and whilst he doesn't torment the cat as such, she does spend more time than she would like avoiding his enthusiastic petting etc. I know we spend much less time fussing over her since having DS...
Any ideas?

We had one who started to vomit a lot as he got older. Maybe not every day though. We never could find anything wrong and he lived, quite happily, to 18.

How does she seem otherwise? Does she have a good appetite? Does she appear to be uncomfortable at all?

Stupid suggestion but you haven't started buying any new flowers/using any new cleaning products that she might be eating/licking?

As for your idea of a protest vomit - well, I guess it could be a stress reaction. You probably can't stop your DS from giving the beloved cat "tokes" but perhaps you could make sure you spend a bit of extra time with her after he's gone to bed each day or while he's napping?

Thanks marzipanned, good to know it could be harmless vomiting, as it was in your cat's case. She's absolutely fine in herself, brought a couple of mice in last week so full of the usual beans. We're not using anything new in the house, nothing's changed apart from DS taking more of an active interest in her really! Unless she's visiting/eating elsewhere, I suppose....

She does bolt her food somewhat, which I thought might be the problem but its usually a long time after food that she will barf so I'd kind of ruled that one out.

We do have a bit of cat fuss time each evening after DS has gone to bed, and she does sleep on our bed at night - even though she threw up spectacularly on the duvet between me and DH at 2am last week...

I'm always amazed at how much cats vomit. Having a house of 20 or so cats there is never a day goes by that I don't have to clear up at least one pile of vomit. Once when my Mum came to stay one vomited in her shoe ... If people vomited as frequently as cats our pavements would constantly resemble those of Watford Town centre on a Saturday night:)

It's very rarely that it seems to be related to any medical condition, it just seems to be something cats do, and some do it more than others.

at cat vomiting in your mums shoe catneuterer - though not so funny for your mum obviously. maybe we will have to just accept we have a vomity cat and invest in super strength carpet cleaner. Or get rid of the carpet...

We had this problem with an 8 year old neutered female. Had bloody expensive tests and thank heavens nothing wrong so vet suggested a change of diet.

Now on Hill's prescription I/D diet - fantastic, get it off the internet - miles cheaper than the vet. Only time she has been sick since is when she stole some turkey or pinches a bit of her brothers food - have to watch her like a hawk.