I have a 9 yr old puggle, who is overweight, but on a diet, but she's been doing a lot of gagging and dry heaving, any ideas what could be wrong?

None at all. Could be many things, could be the heat, could be the diet she's on, could be many things. Really, we can't diagnose online. If this is a concern you should take her to the vet.

Good luck.

The symptoms you are describing could indicate a heart problem. This is even more suspect because she is overweight. It is important that she receive medical treatment and advice as soon as possible. Please make an appointment with your vet quickly.

I hope this helps and please let us know what the vet says.

Hugs, Didi