My dog is throwing up.

Question
My has been throwing up since Wednesday and it is now Friday early morning. I have discovered on this early hour 3 more pools of throw-up.

Is it time to go to the vet?

Let me explain why I am delaying the visit to the vet. About 2 months ago, I want to say almost the exact same thing happened and we followed the vet's orders to give her the bland meal of boiled white rice and breast chicken. And yes, she got over it ok.

Either case, what is normal throwing up for a dog; my dog is a Toy Poodle. Because, every now and then, sometimes as often as once a week, my dog throws up a meal or whatever it is causing her to throw up.

Now getting back to my dog being sick again right now. She had her vaccines on Tuesday December 12th; she is 2 years old. We flew from Toronto to Fort Myers, Florida on Friday the 15th. Right away I noticed that the first two days she passed very little stool; maybe once between Friday through Sunday. Also on Saturday we bought her a different brand of dog food from what she'd been eating in Toronto; from Iams Adult Dog Food to Castor and Pollux Petworks Natural Ultramix. I noticed that when she finally started passing stool after Sunday, the first time, she took almost 15 minutes squatting and obviously having difficulty. That was the only time and now up till this very morning, she has been passing very very soft, some parts look dark red in color. I don't know if it's because I didn't follow the directions on the new dog food package about mixing it in slowly with her old dog food for several days until she got used to it. To be honest I have never really done that. Before our visit to Toronto of 2 months, my dog has been on Science Diet dog food. Is it important to slowly introduce your dog to new dog food? If you don't, can it make them throw up/reject the new food in the way that my dog has been sick?

During this whole time, when she throws up, she throws up until there's nothing left in her stomach to throw up and only liquidly stuff is thrown up.

Again yes, all the same symptoms happened exactly about 2 months ago. And this is what brings me to ask for help on the matter because I want to understand if it's something she ate that was bad for her be it while we
are out walking or if it's something bad she ate around the house or the backyard. Is it possible for dogs to eat something bad for them and get a stomach irritation as a result? Or does this all sound like something uncommon altogether for a dog?

Finally I should also mention that when I do talk to her and whenever I do initiate interaction with her, she is fine; she still plays, she still seems alert; only maybe yesterday she's starting to seem tired from not holding any of her food down.

Please help me help my best friend. Thank you for any help or research you can give me.

Answer
Hello,
      Yes this sounds a bit serious. I advise you to bring her to the vet, it's the only way. Tell your vet all the things you told me and I'm sure he/she will soon find something that will help. Good luck and best wishes!
                       -Shannon