Hi everyone, I (30M) wanted to have advice concerning my cat(11 years old female, 17 lbs). I'm in Canada and have access to a vet put before spending 100+ $, I was wondering if it could be normal/resolve by itself or if a consult would be better.

2 1/2 weeks ago, I went to the vet because my cat was eating less (like 50 % of her normal ammount) and having diarhea. The vet told me it's was probably a stomach bug and gave me mirtazapine and another pill for nausea. The combo worked great and she went back to her normal self.

Since thursday last week, she begane to eat a little bit less (not that much), but what concerned me the most is that she meow to me like she is really hungry, I feed her, she will eat 30 to 40% of whatever I give her (dry or wet food), go lay down for a little while then comeback and eat a little bit again to finish (or almost) what was left. She normally devorer everything. 

This weekend I (after calling the vet to make sure it was safe) gave her another mirtazapine to stimulate her appetite and if work maybe too well, she ate as usual and was asking for more.

Now the pill seems to have wear off and she is back to not eating all her food all at once.

She always or almost always finish her food and eat maybe a little less but not that much of a difference.

Otherwise no change except she play maybe a little bit less.

Since she is a fat cat I know there could be problem if she doesn't eat enough that's why I'm concerned. She also has an history of tartar but the vet told me it could be dangerous to clean her teeths but of anesthesia. Could it be that?

I don't really have the capital to invest a lot of money so trying to be proactive but it's stressing me.

Thanks everyone and sorry if something are weirdly written, english is not my first langage.

Should ai be concerne