What Chemicals in Mouthwash Are Toxic to Dogs?

Mouthwash formulated for people may freshen your breath, but it's unfortunately not appropriate for making Fido's breath smell better. Human mouthwash contains chemicals that are potentially toxic to your dog if he swallows it. For your pup's safety, keep your mouthwash away from him -- use only canine-specific oral rinses in his mouth.

The main ingredients found in most human mouthwashes include water, alcohol, fluoride, salt, antimicrobial substances and odor neutralizers, along with flavoring and coloring agents, according to the American Dental Association. Alcohol, fluoride and salt are considered toxic to dogs, warns the Pet Poison Helpline. Xylitol, a sugar substitute frequently used to flavor mouthwash, is highly toxic to Fido. You may also find hydrogen peroxide in your mouthwash because of its antimicrobial properties. This chemical is commonly used to induce vomiting in dogs because it causes mild gastric irritation, making it somewhat toxic to them, according to the Veterinary Support Personnel Network.

To avoid poisoning your pup, keep your mouthwash bottle closed and away from his access. Never leave a cup of mouthwash lying around where Fido can lick it. While a small amount of mouthwash may cause only mild gastrointestinal distress, if Fido drinks a lot of it, visit your vet so she can care for him. Consult with your vet if you're concerned about Fido's breath. She can recommend a canine-specific product to use or may perform a dental cleaning to freshen his breath safely.