Hydrogen peroxide is a godsend, please do keep it on hand! Howie ate an entire bottle (about 2.5 months worth) of prescription meds last spring. Luckily I discovered what he had done very, very quickly and, after a call to the emergency vet, administered the hydrogen peroxide. We had immediate projectile vomiting! He spent the day at the vet being observed (but cost no $$$ since he is such a good customer!) and I had to explain a strange situation to my own doctor. It was an experience that could have been horrible!