Question: is it safe to put hydrogen peroxide in your dog's mouth?
Answer: Make sure you have a 3-percent hydrogen peroxide solution. Higher concentrations are toxic and can cause serious damage. Administer the proper amount: the suggested dosage is 1 teaspoon per 5 pounds of the dog's body weight by mouth, with a maximum dose of 3 tablespoons for dogs who weigh more than 45 pounds.