Dog throwing up for 2 1/2 weeks...what should I do?

I have a dog: a girl, 3 years old, a lab/doberman cross (I think) who's been throwing up for the past 2 weeks. I have taken her in to the vet and had her checked out. Everything appeared to be normal.

She has not shown major signs of malnourishment, but if she continues not to keep anything down, she will start showing it. She is a little skinnier, which is well understandable, not really keeping anything down for awhile.

The vet had me change her food (again, about 2 weeks ago) to Hill's Prescription Diet I/D formula, and I have tried both the canned and regular versions, neither have worked. I also have tried just feeding her chicken to see if there is something in the food being given her that is causing an allergic reaction. Speckles (my dog's name) has kept a little bit of food down during the 2 1/2 weeks of sickness, but lately (the past couple days) has not kept anything down at all.

I brought in a stool sample to the vet, and he did not find any worms or anything abnormal. She has been going to the bathroom, so I know something's getting through.

Have any of you had these symptoms with your dog? I'm concerned that she needs to start keeping things down. I did get medication today (Sucralfate) that is supposed to help if it is a cyst or something along those lines. I would greatly appreciate your response. I believe my next (and last) option is x-rays, which can be pricy, but I may just have to go with it.

Thank you all so much for your time!
~Bekah

Hi there - I keep this website on hand for referral and find it quite helpful - I looked up "chronic vomiting" and came up with the following:
http://www.vetmedcenter.com/Consumer/display.asp?id=8655&dt=p

Hope that helps; you can ask your vet if any of these conditions may apply to Speckles.

Hope you can get this figured out!

Thank you all so much again!! I was almost sure that there was an obstruction. Until today...

I called around to different vet clinics and priced X-rays, blood work (which, by the way, had not been done yet!), and office visit costs. There was one place noticeably cheaper then others, but yet were well-equipped.

One thing that really impressed me about this animal hospital versus the others that I called was the care and concern that the people there had. Other places were more like, "Well, I can't really price it, but here's an estimate. Have a nice day." But the lady that I talked to at this hospital said that it would not be good to wait another day, and that if at all possible, I should get my dog in there right away.

I was able to work things out, and get Speckles in to the hospital. The way that they do things there is you drop your pet off, and they keep them for however long they need to. Not like the typical clinic where they say to come for about half an hour and see how much they can cram in that small amount of time.

Anyway, after a 6-hour visit, I went and picked Speckles up. She was obviously very happy to see me!

The procedures that were done were: general health examination/overview ($82.50), Daily Prof. evaluation and care ($8.30), X-ray 2 views ($66.00), and overdue distemper shot (oops on my part!) ($22.00). The office visit was $22.00.

The blood work was normal. Nothing turned up there. Nothing showed up on the x-rays that they were able to see; although they did say that they'd have to refer me on to get barium study and endoscopy if the information and diagnosis that they gave to me doesn't work.

Ok, now for the diagnosis. They said that Speckles has an ulcer on the roof of her mouth which appears to be healing. So she probably got into something that burned her mouth, which in turn made an ulcer in her stomach also. ("Suspect a caustic toxin causing gastroenteritis.") They prescribed two meds: Cimetidine and Metoclopramide. The vet also had me change food.

So, I am gladly hoping that everything was cleared up and we're on the way to recovery.
Thanks again for your posts, concern, and advice. It's all greatly appreciated!