Is Peppermint Safe for Dogs? Mint Leaves, Peppermint Oil and Breath Mints

Whether peppermint is safe for dogs depends on its form. The ASPCA lists garden mint as toxic to dogs, noting that eating large amounts can cause vomiting and diarrhea. Peppermint oil is riskier: VCA lists it among essential oils toxic to dogs. Human breath mints and sugar-free candy can be the most dangerous because they may contain xylitol. Merck says xylitol can cause low blood sugar within 30 minutes.

Key points

• Eating large amounts of garden mint can cause vomiting and diarrhea, and no source gives a safe number of leaves.
• Never use peppermint oil on or in your dog. Even a few licks or a small amount on the skin could be harmful.
• Sugar-free mints, gum, and toothpaste can contain xylitol. Merck links doses above about 45 mg per pound of body weight to low blood sugar.
• After any contact with xylitol or peppermint oil, call your vet or ASPCA Animal Poison Control at (888) 426-4435, even if your dog seems fine.
• Do not make your dog vomit unless your vet or poison control tells you to.
  

Is peppermint safe for dogs? It depends on the form

The plant, the oil, and human mints each carry different risks, and no safe amount has been established for any of them. Many owners ask about mint because of bad breath. If that is why you are considering it, start with what usually causes bad breath in dogs.

The following table compares the forms owners ask about most and includes a source for each row:

Form	Main risk	What the sources say	What to do
Fresh or garden mint leaves	Stomach upset	The ASPCA's mint entry lists garden mint as toxic to dogs; the signs are vomiting and diarrhea after large amounts.	Call your vet or poison control if your dog ate a large amount.
Peppermint oil and other essential oils, by mouth, on the skin or in a diffuser	Poisoning, and irritation or burns of the skin and mouth	VCA lists peppermint oil as toxic to dogs; a few licks or a small amount on the skin could be harmful.	Do not use it on or in your dog. After any contact, call your vet or poison control now. Ask your vet before running a diffuser in a room your dog uses.
Sugar-free mints and gum	Xylitol: low blood sugar, and liver failure in some dogs	Merck's xylitol chapter says signs of low blood sugar can start within 30 minutes, and some dogs that eat large amounts may develop severe liver failure.	Call your vet or poison control now, even if your dog seems fine.
Peppermint candy, chocolate mints and peppermint bark	Xylitol in sugar-free candy; chocolate	The ASPCA's people-foods list says chocolate can cause vomiting, tremors, seizures and even death, and darker chocolate is riskier.	Check the label for xylitol and chocolate, then call your vet or poison control.
Human toothpaste and mouthwash	Fluoride or xylitol	The ASPCA's household products list notes that toothpaste can contain fluoride or xylitol.	Use a veterinary toothpaste. Call if your dog ate a large amount or the label lists xylitol.
Dog treats that list dried peppermint leaf	Unknown: no source gives an amount for dogs	The ASPCA lists mint as toxic, with signs after large amounts. The amount in a treat is on its label.	Check the amount on the label, and ask your vet first if your dog has a sensitive stomach.

Is peppermint toxic to dogs?

Yes. The ASPCA lists mint as toxic to dogs and identifies its essential oils as the toxic component. Peppermint oil is a concentrated form of that oil, and VCA lists it among essential oils toxic to dogs.

What happens if a dog eats peppermint?

It depends on the form and amount. Eating a large amount of the plant can cause vomiting and diarrhea. Peppermint oil can cause drooling, tremors, and burns in the mouth. Xylitol in sugar-free mints poses a separate, greater danger. Merck says it can cause low blood sugar and, in some dogs, severe liver failure.

Can dogs have mint leaves?

It is best not to offer mint leaves. The ASPCA lists garden mint (Mentha species) as toxic to dogs, cats, and horses because of its essential oils. Eating large amounts can cause vomiting and diarrhea.

No safe amount of fresh mint has been established for dogs, so there is no recommended number of leaves to offer.

Is it bad if my dog ate mint leaves from the garden?

The amount matters. The ASPCA lists vomiting and diarrhea after dogs eat large amounts, so watch for those signs. If your dog ate a large amount, or you are unsure how much, call your vet or ASPCA Animal Poison Control at (888) 426-4435. The line is open 24/7, and a consultation fee may apply.

Keep pennyroyal away from dogs

Pennyroyal oil is among the essential oils that can damage the liver, according to the Merck Veterinary Manual. VCA also lists it as toxic to dogs. Keep pennyroyal products away from your dog, and call your vet or poison control if your dog gets into any of them.

For information on other kitchen herbs, read whether chamomile tea is safe for dogs.

Why peppermint oil is the bigger danger

Peppermint oil concentrates the part of the plant that makes mint toxic. VCA warns that even a few licks or a small amount on the skin could be harmful, depending on the ingredients and how the dog is exposed.

The Merck Veterinary Manual explains that essential oils are quickly absorbed through the gut, skin, lungs, and mucous membranes, such as the lining of the mouth. VCA adds that many are processed by the liver, and some can irritate or burn the skin and mouth.

Peppermint is not the only oil on VCA's list. It also includes oils of cinnamon, citrus, pennyroyal, pine, sweet birch, tea tree (melaleuca), wintergreen, and ylang-ylang.

Can I put peppermint oil on my dog for fleas?

No. Do not apply peppermint oil to your dog's skin or fur, including homemade flea sprays and diluted mixes. VCA warns that even a small amount on the skin could be harmful, depending on the ingredients and how your dog is exposed.

Signs of essential oil poisoning

VCA lists these signs:

• The scent of oil on the coat, skin, or breath
• Difficulty breathing
• Difficulty walking or uncoordinated movements
• Drooling
• Low energy or weakness
• Muscle tremors
• Pawing at the mouth or face
• Redness or burns on the lips, gums, tongue, or skin
• Vomiting

Call your vet or ASPCA Animal Poison Control at (888) 426-4435 now. Merck adds that some cases lead to seizures, liver failure, or kidney failure.

Is peppermint oil safe for dogs to smell?

Do not assume it is safe. Merck notes that essential oils are absorbed through the lungs. Ask your vet before using an essential oil diffuser in a room your dog uses, and keep diffusers and oil bottles out of reach.

First aid for peppermint oil on the skin or fur

Wash the oil off quickly with liquid dishwashing detergent, then call your vet or poison control. Do not make your dog vomit or give activated charcoal, as VCA warns that these actions may make your dog worse. Merck also advises against inducing vomiting because your dog could breathe vomit into the lungs.

Can dogs have breath mints or peppermint candy?

No. Human breath mints, sugar-free gum, and candy can contain xylitol, which can cause low blood sugar in dogs. In some dogs that eat large amounts, it can also cause severe liver failure.

What xylitol does to a dog

According to Merck's xylitol chapter, signs of low blood sugar can begin within 30 minutes. These include vomiting, weakness, wobbliness, lethargy, seizures, and coma. Signs may be delayed up to 12 to 18 hours if xylitol is in a product that slows absorption, such as some gums.

Cornell's Riney Canine Health Center says signs often begin within 30 to 60 minutes. Some dogs that eat large amounts may develop severe liver failure. The ASPCA says liver damage can occur within 12 to 24 hours.

Merck links doses above about 45 mg per pound of body weight (100 mg/kg) to low blood sugar. It also says some dogs that eat more than 227 mg per pound (500 mg/kg) may develop severe liver failure.

Cats are not at risk from xylitol: Merck says dogs are the only domestic species in which xylitol poisoning has been reported.

How little xylitol can harm a dog

The table applies Merck's two thresholds to common dog body weights. It shows how little xylitol can cause harm, not a safe amount.

Dog weight	May cause low blood sugar (about 45 mg per pound)	May cause liver failure in some dogs (about 227 mg per pound)
5 lb	0.2 g	1.1 g
10 lb	0.5 g	2.3 g
20 lb	0.9 g	4.5 g
40 lb	1.8 g	9.1 g
60 lb	2.7 g	13.6 g
80 lb	3.6 g	18.2 g

Any xylitol: call now. Do not use this table to decide to wait.

What is the outlook after xylitol poisoning?

With prompt treatment, the outlook for uncomplicated low blood sugar is good, Merck says. But in one report, 62.5% of dogs with signs of liver injury died or were euthanized, despite aggressive veterinary care. Cornell adds that most dogs receiving aggressive treatment recover, while those that develop liver injury may have a less certain outlook.

Chocolate mints and peppermint bark

These add a second toxic ingredient: chocolate. It contains methylxanthines, which the ASPCA says can cause vomiting and diarrhea, panting, excessive thirst and urination, hyperactivity, an abnormal heart rhythm, tremors, seizures, and even death. The darker the chocolate, the greater the risk. To estimate the risk from chocolate, use the dog chocolate toxicity calculator.

Can dogs eat candy canes?

Keep them away from your dog. Sugar-free candy canes can contain xylitol, and chocolate-dipped ones add the risk of chocolate poisoning. If your dog ate one, check the label and call your vet or poison control immediately if it lists xylitol or chocolate.

What to do if your dog ate peppermint, mints or peppermint oil

Keep the package, check the label for xylitol and chocolate, and call your vet or ASPCA Animal Poison Control right away. Do not wait for signs, because xylitol poisoning signs can be delayed.

Save these six steps:

1. Move your dog away from the product and keep the package.
2. Check the label for xylitol and chocolate.
3. Call your vet or ASPCA Animal Poison Control at (888) 426-4435 at once. The line is open 24/7, 365 days a year, and a consultation fee may apply.
4. Do not make your dog vomit unless your vet or poison control tells you to.
5. If oil is on the skin or fur, wash it off with liquid dishwashing detergent.
6. Go to the vet at once if you see vomiting, weakness, stumbling, tremors or seizures.

Step 4 matters for both oils and xylitol. VCA warns that inducing vomiting after essential oil exposure may make a dog worse. For xylitol, Cornell says a vet will likely induce vomiting only if the dog ate it less than 30 minutes earlier and shows no signs of low blood sugar.

According to Merck, signs can be delayed up to 12 to 18 hours when xylitol is in a product that slows absorption, such as some gums. Even if your dog looks fine, you still need to call.

Is mint toothpaste or mouthwash safe for dogs?

No. Human toothpaste, mint-flavored or not, can contain fluoride or xylitol. Use veterinary toothpaste to brush your dog's teeth instead.

The ASPCA says dogs usually do not swallow enough fluoride to develop significant signs of poisoning. A large amount can cause severe stomach upset, irregular heartbeats, low blood pressure, and life-threatening electrolyte changes. Merck lists toothpastes and other oral hygiene products as sources of xylitol, so keep mouthwash away from your dog, too.

Cornell's Riney Canine Health Center says brushing once a day with veterinary toothpaste is important for your dog's dental health.

Does peppermint freshen a dog's breath?

A mint flavor can only mask the smell. Most bad breath starts in the mouth, where bacteria build up in a film on the tongue and gums. UC Davis says gum disease can be the main source.

 

If your dog's breath continues to smell bad, book a vet exam. The bad-breath article linked near the top of this page explains the likely causes.

Peppermint leaf in dog chews

Some breath chews for dogs use dried peppermint leaf for flavor. Dried leaf is different from peppermint oil, the concentrated form that VCA lists as toxic. Still, no source gives an amount of either for dogs.

If you want a breath chew for your dog's daily routine, read the label first. HolistaPet makes Fresh Breath Soft Chews, which contain peppermint leaf powder, spirulina, coriander, kelp, parsley, and beneficial bacteria. They are made to freshen breath as part of daily care. Check the amount of peppermint leaf listed on the label, and ask your vet first if your dog has a sensitive stomach.

Sources

1. ASPCA Animal Poison Control Center. Mint (Toxic and Non-Toxic Plant List). Undated.
2. VCA Animal Hospitals. Essential Oil and Liquid Potpourri Poisoning in Dogs. 2026.
3. Merck Veterinary Manual (Veterinary Version). Xylitol Toxicosis in Dogs. 2024.
4. ASPCA Animal Poison Control Center. People Foods to Avoid Feeding Your Pets. Undated.
5. ASPCA Animal Poison Control Center. Poisonous Household Products. Undated.
6. ASPCA Animal Poison Control Center. ASPCA Poison Control. Undated.
7. Merck Veterinary Manual (Veterinary Version). Toxicoses From Essential Oils in Animals. 2025.
8. Cornell University College of Veterinary Medicine, Riney Canine Health Center. Xylitol Toxicities. Undated.
9. Cornell University College of Veterinary Medicine, Riney Canine Health Center. Periodontal Disease. Undated.
10. UC Davis School of Veterinary Medicine (Animal Health Topics). Halitosis in Dogs. 2026.