vomiting

I have a 5 month old toy poodle. This past saturday he starting vomiting. The vet told me to give him a little bit of petobismol 15 minutes before he eats his food and to split it in half each time i feed him. The peptobismol made is vomiting worse. They said that it might be acid because he eats his food really fast. We are still feeding him in small portions and when he eats in the morning he is fine he doesn't vomit all day while we are gone but he eats again at 5 in the evening and about 5 hours later he vomits some of it back up. He doesn't have diarrhea or anything like that. He doesn't seem to be sick other than the vomiting he plays and drinks his water like he always has. I am at a loss as to what may be wrong. Is there any suggestions as to what may be wrong. Please help.

[Aleda M Cheng, D.V.M., C.V.A]

This is a tough one, because your dog is so young.  It is unusual that he only vomits after his evening meal.  It could be food hypersensitivity, parasites, a stomach bug, a foreign body, or more.  You could try a hypoallergenic puppy food, or food for sensitive stomachs.  You may not be able to find these for puppies, so you may have to supplement with a vitamin/mineral supplement.  I would also have a regular fecal and a giardia test, even if he has tested negative for parasites in the past.  Your vet may want to give him a short course of Panacur (anti-parasitic) to empirically treat for some hidden parasites.  I would also add a probiotic to his diet such as RX Biotic, I-Flora or Culterelle.  Lastly, he may just have a stomach bug since it has only occurred for a week that may just pass on it's own.  Good Luck!