The toxins in chocolate are theobromine and caffeine. Their effects are dose dependent. Pure cocoa and dark chocolate have much more of these toxins than milk chocolate, which is mostly sugar and milk. If your pet has eaten dark chocolate, baker's chocolate or pure baking cocoa you may have a toxic problem. If it has been less than 20 minutes from the time the pet has eaten the chocolate, then make your pet vomit. You may use hydrogen peroxide. Give hydrogen peroxide by mouth until your pet starts to vomit. See chart below for hydrogen peroxide doses. Try to note the amount of material brought up. After the vomiting, do not feed and give water only for 12 hours then start a bland diet the next day. If your pet has consumed a significant amount of chocolate and it has been greater than 20 minutes, call the hospital for instructions and possible admittance for supportive care.
Use a childrens dosing syringe or chicken baster to give the hydrogen peroxide. Give the dose once, wait 10 minutes, then repeat if the dog has not vomitted yet. Call the hospital if no vomit occurs after 2 doses of hydrogen peroxide.
2-10 lbs: 1 tbsp by mouth
10-25 lbs: 2-4 tbsp by mouth
25-50 lbs: 3-5 tbsp by mouth
50-100 lbs: 1/2 cup-3/4 cup by mouth
> 100 lbs: 1 cup by mouth