My old dog is always throwing up her food...

I've got an a 11 year old rottweiler that can almost never keep her food down. She was kind of overweight before but she has lost a lot of weight. I took her to the vet and they did bloodwork and said everything was fine there and that she probably had acid reflux. It seemed like the medicine was working for a couple of days but now she's back to throwing up almost all of her food. 

I'm scared this might be the end of the line for the old girl. Has anyone else had this problem and what did you do to remedy it?

Change her food until you find something she can tolerate.
Consider the raw food diet for her. Google it, lots of good info. Phone Post 3.0

If you have the money, I would take her to another vet to get a second diagnosis. Not being able to keep her food down might be something serious. Phone Post 3.0

I would definately get a second opinion.
Had a Husky who couldn't keep anything down. Turns out his Kidneys were starting to fail. After a week of being in the vets and the wife and I having to perform "doggy dialysis" for a week, we ended up having to put him to sleep.

Hopefully you can catch this early and do something about it. I don't think we caught it soon enough.

Good luck.

Also could be a partial digestive blockage if the vet didn't do any imaging to rule it out.

I agree with a second opinion. Good luck. Phone Post

Well they did bloodwork to see if it was a kidney problem and they said that was normal. I am probably going to try to switch her food around and see if that makes a difference. 

eating too fast? I thought kidneys but if values are good that's great.

don't switch food too abruptly or it will be coming out the other end

She used to eat fast so I thought maybe that was it but now I give her small amounts at a time and she still gets sick.