diarrhea and vomiting in dogs

my chihuahua has been vomiting and having diarrhea for about two days now. i dont know what she ate that is making her sick. I wanted to know if there is any human product like Alka Seltzer or Pepcid AC that i can give my dog to help her upset stomach.

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

Over the Counter regular Pepcid (not pepcid ac) is used in dogs and cats all the time.  A dose for a chihuahua would be very small, obviously.  The Pepcid dose is:0.25 to 0.5 mg per pound.  If she weighs 3 pounds you would give 0.75 to 1.5 mg's once daily.  If you could find a pediatric or liquid Pepcid it would be easier to give this tiny dose.

She should really go to the vet, though.  Seemingly simple gastrointestinal upsets or dietary indiscretions can lead to more serious diseases such as pancreatitis, in some cases.  If she doesn't get well quickly, please take her to the vet.