The short answer
Never give your dog a human medicine unless your vet tells you to, at that dose, for that dog. Pain relievers such as ibuprofen, naproxen and acetaminophen, ADHD stimulants, antidepressants, sedatives, heart pills and anything sweetened with xylitol can poison a dog. One tablet can be enough. If your dog swallows something, call your vet or a pet poison line now. Do not wait for signs. Ask your vet which medicines are safe for your dog and how to store the rest.
Key takeaways
- In the ASPCA’s 2024 data (U.S.), over-the-counter human medicines ranked first among pet poisoning exposures, at 16.5% of all exposures. Human prescription medicines ranked third.
- Dogs do not process human drugs the way people do. Pet Poison Helpline says naproxen has a narrow margin of safety, and that one 220 mg tablet can cause very serious signs, even in a large dog.
- Xylitol, a sugar substitute in gum, mints, some vitamins and nasal sprays, can drop a dog’s blood sugar within 10 to 15 minutes of eating it.
- Cold and flu products can hide acetaminophen. Read every ingredient on the label before you call, and bring the package.
- Two North American pet poison lines are listed by the Ontario SPCA and the University of Guelph. Both may charge a fee. Your own vet or an emergency clinic is the other call to make.
- Only your vet can say whether a human-use medicine is right for your dog. Dose, form and timing all change for dogs.
Why a small amount can still be dangerous
A dog is not a small person. Body weight is one reason. The way a dog’s body breaks down a drug is another. Pet Poison Helpline says acetaminophen has a narrower margin of safety in dogs than in people, and that cats are the most at risk. It describes naproxen as very poisonous to dogs and cats because of its narrow margin of safety.
Most poisonings are accidents, not mistakes in dosing. A pill drops on the kitchen floor. A weekly pill organiser sits on a low table. A purse hangs open on a chair. A puppy that is teething will chew anything it can reach. If you are bringing a puppy home, the guides on puppy-proofing a Canadian home and yard and toxic foods and household hazards cover the rest of the house.
The numbers back this up, with one caution. The ASPCA Animal Poison Control Center publishes the most detailed public data, and it is a U.S. service. Its 2024 list put over-the-counter human medicines at the top, at 16.5% of all exposures. Human prescription medicines ranked third, with heart medicines, antidepressants and ADHD medicines the most commonly involved. We found no equivalent Canadian count, so treat the percentages as U.S. figures.
The 10 to keep locked away
This table lists ten groups of human medicine and what the poison services say about each. It is a starting list, not a full one. If a medicine is not here, do not assume it is safe.
| Medicine | Common names | What the sources say can happen | Source |
|---|---|---|---|
| 1. Ibuprofen | Advil, Motrin | Stomach and bowel ulcers (vomiting and diarrhea with blood), kidney damage, and nervous system signs that can include coma. Pet Poison Helpline says it should not be given to pets. | Pet Poison Helpline |
| 2. Naproxen | Aleve, Midol | Stomach and bowel ulcers that can perforate, and sudden kidney failure. One 220 mg tablet can cause very serious signs, even in a large dog. | Pet Poison Helpline |
| 3. Acetaminophen | Tylenol, Excedrin, Percocet | Stomach upset, blood changes and liver failure. The margin of safety is narrower in dogs than in people. Cats are most at risk. | Pet Poison Helpline |
| 4. Aspirin (acetylsalicylic acid) | Many brands | Dogs are less sensitive than cats, but poisoning still occurs. Signs include stomach signs, a raised body temperature and kidney failure. Vets sometimes use aspirin at set doses. Do not dose it yourself. | Pet Poison Helpline |
| 5. ADHD stimulants (amphetamines) | Prescription only | Agitation, restlessness, vomiting, a fast heart rate, high blood pressure and a dangerously high body temperature. The ASPCA names ADHD medicines among the most common prescription exposures (U.S.). | Pet Poison Helpline |
| 6. Antidepressants | Prescription only | The ASPCA names antidepressants among the most commonly involved prescription medicines (U.S.). Ask your vet or a poison line about the specific drug. | ASPCA (U.S.) |
| 7. Sedatives and anti-anxiety drugs (benzodiazepines) | Xanax, Valium, Ativan, Klonopin | Agitation or depression of the nervous system, and stomach and bowel signs. In severe cases, slowed breathing and heart function. | Pet Poison Helpline |
| 8. Heart and blood pressure pills (beta-blockers) | Prescription only | A slow heart rate, dangerously low blood pressure, and in some cases heart or kidney failure. Even a small overdose can be life-threatening. | Pet Poison Helpline |
| 9. Anything with xylitol | Gum, mints, some chewable vitamins, fish oils, nasal sprays, toothpaste | Life-threatening low blood sugar within 10 to 15 minutes, and acute liver failure. Xylitol content varies widely, even between flavours of one brand. | Pet Poison Helpline |
| 10. Combination cold, flu and pain products | Many brands | These can contain acetaminophen or other active ingredients in one tablet. Pet Poison Helpline lists cold, flu, allergy and fever products as sources of acetaminophen. | Pet Poison Helpline |
Decongestants and sleep aids are missing from this table on purpose. We did not find a readable Pet Poison Helpline page for either, so we do not state their effects. Do not give them to a dog, and call your vet if your dog swallows one.
What to do if your dog swallows a human medicine
- Take the medicine away. Check your dog’s mouth for pieces and keep other pets back.
- Call now. Phone your vet or an emergency clinic. If you cannot reach them, call a pet poison line (numbers below). Do not wait for signs. Xylitol can lower blood sugar within 10 to 15 minutes, and some drugs act just as fast.
- Have the facts ready. Name of the medicine, strength on the label, how many tablets or how much liquid may be missing, when it happened, your dog’s weight and age, and any medicines your dog takes.
- Bring the package. Take the bottle, blister pack or wrapper to the clinic. Combination products list every ingredient on the box.
- Follow the instructions you are given. Do not induce vomiting unless a vet tells you to, and do not give any antidote unless a vet or poison line tells you to. The right step depends on the drug and on how long ago your dog ate it.
Who to call
| Service | Phone | What the source says |
|---|---|---|
| Pet Poison Helpline | (855) 764-7661 | Open 24 hours. Its site says a $99 incident fee applies and does not name the currency. The University of Guelph lists it by name; the Ontario SPCA lists the same number as a 24/7 Animal Poison Control Center. |
| ASPCA Animal Poison Control Center (U.S.) | (888) 426-4435 | Open 24 hours, every day of the year. A consultation fee may apply. The Ontario SPCA and the University of Guelph both list it. |
| Your own vet or the nearest 24-hour emergency clinic | Find the number before you need it | A poison line gives advice. Your vet can examine your dog. See the guide on choosing a vet and what the first visit covers. |
None of the pages we read states whether these lines take calls from Canada or what the fee is in Canadian dollars. Ask when you call. Save both numbers, and your clinic’s after-hours number, in your phone today.
Keep medicines out of reach: a home checklist
- Store every medicine, vitamin and supplement in a closed cabinet or a high shelf. A bathroom counter is within reach of a dog that jumps.
- Use pill organisers with the lid shut and put them away after each use. Dogs can chew through a plastic lid.
- Keep purses, backpacks and jackets with pills in them off the floor, including at the homes of family and friends.
- Pick up dropped pills at once. Check under the couch and the fridge.
- Read the label for xylitol before you bring gum, mints, chewable vitamins or nasal sprays into a home with a dog.
- Tell guests, house sitters and dog walkers which medicines are in the home and where they are stored.
- If your dog has its own prescriptions, keep them apart from yours and label them. See senior dogs: what changes after age seven.
What about dog-safe versions?
Some medicines are used in both people and dogs. The dose, the form and the schedule differ. Aspirin is one example. Pet Poison Helpline notes that aspirin can help with pain from osteoarthritis at appropriate doses in pets, and it is still on the list above. Your vet may prescribe a dog-specific pain medicine, an antihistamine or a behaviour medicine. Use only what your vet prescribes, at the dose and for the length of time on the label. Do not split or share your own pills. Ask the vet before you add any supplement, including over-the-counter ones. If your puppy came home with a first-visit plan, ask the vet which medicines belong on it. The first-year vet visit guide shows what to expect.
Myth vs fact
| Myth | Fact |
|---|---|
| A tiny dose will not hurt. | Pet Poison Helpline says one 220 mg naproxen tablet can cause very serious signs, even in a large dog. |
| If my dog acts normal, it is fine. | Xylitol can lower blood sugar within 10 to 15 minutes. Call first, then watch. |
| Over-the-counter means safe. | In the ASPCA’s 2024 data (U.S.), over-the-counter medicines ranked first among pet poisoning exposures. |
| What works for me works for my dog at a smaller dose. | Dogs process drugs differently. Dose, form and timing are set by a vet for each dog. |
| Cats and dogs react the same way. | Pet Poison Helpline says cats are the most at risk from acetaminophen and more sensitive than dogs to aspirin. |
| Only pills are a risk. | Gum, nasal sprays, topical products and liquid medicines can all matter. Pet Poison Helpline lists topical medications and liniments among sources of aspirin. Check labels for xylitol and for active ingredients. |
Frequently asked questions
Can I give my dog Tylenol or Advil for pain?
No. Do not give acetaminophen, ibuprofen or naproxen to a dog unless your vet tells you to. Pet Poison Helpline says ibuprofen should not be given to pets. If your dog seems to be in pain, call your vet. They can find the cause and prescribe a pain medicine made for dogs.
What if my dog ate one pill and seems fine?
Call your vet or a pet poison line anyway. Give the medicine’s name and strength and your dog’s weight. One tablet can be enough to cause serious harm for some drugs, and we found no source that sets a safe amount.
Should I make my dog vomit?
Do not induce vomiting unless a vet or a poison line tells you to. The right step depends on the drug, the amount and the time since your dog ate it. Some situations make vomiting unsafe. Ask your vet to explain the steps for your dog.
Are the poison lines free?
No source we read says they are free. The Pet Poison Helpline ibuprofen page says an incident fee applies, and the ASPCA says a consultation fee may apply. Ask about the fee at the start of the call.
Is xylitol only in gum?
No. Pet Poison Helpline lists gum and mints, but also candies, puddings, sauces, jams, toothpaste, oral rinses, sugar-free chewable vitamins and fish oils, nasal sprays and some other products. The amount varies, so check each label.
My puppy is chewing everything. How do I protect it?
Treat every medicine as a hazard and keep all of them in a closed cabinet. Give your puppy chews made for dogs. The guide on what puppies should chew and what to bin has options. The new puppy guide lists every step from first day to first month.
This guide is general information, not veterinary advice. For your dog, ask your vet.
Keep reading
- Toxic foods and household hazards for dogs
- Puppy-proofing a Canadian home and yard
- Emergency signs every owner should know
- When to go to a 24-hour emergency hospital and what it costs
- Choosing a vet and what the first visit covers
Sources
Every link was opened and read in October 2026. Each entry shows the date the page itself gives, where it gives one.
- ASPCA: The Official Top 10 Toxins of 2024 (U.S.; page dated March 13, 2025) (checked October 2026)
- ASPCA Animal Poison Control Center (U.S.; phone line and fee note) (checked October 2026)
- Pet Poison Helpline: ibuprofen (U.S.-based service) (checked October 2026)
- Pet Poison Helpline: naproxen (U.S.-based service) (checked October 2026)
- Pet Poison Helpline: acetaminophen (U.S.-based service) (checked October 2026)
- Pet Poison Helpline: aspirin (U.S.-based service) (checked October 2026)
- Pet Poison Helpline: amphetamine (U.S.-based service) (checked October 2026)
- Pet Poison Helpline: benzodiazepines (U.S.-based service) (checked October 2026)
- Pet Poison Helpline: beta-blockers (U.S.-based service) (checked October 2026)
- Pet Poison Helpline: xylitol (U.S.-based service) (checked October 2026)
- Ontario SPCA: World Animal Day, know who to call (October 4, 2024) (checked October 2026)
- University of Guelph Animal Health Laboratory: poison information centres (checked October 2026)
Keep reading