3. Inducing Vomiting If advised by your veterinarian, you may need to induce vomiting to prevent further absorption of the poison. This can often be done using hydrogen peroxide (3%). The general recommendation is one teaspoon for every 10 pounds of body weight, but this should only be done under veterinary guidance. Do not attempt this if your dog is already lethargic, having seizures, or is unable to stand.