Dog Hydrogen Peroxide Vomiting Calculator
Calculate the correct 3% hydrogen peroxide dose to induce vomiting in your dog. This calculator checks for contraindications before displaying any dose — because not all ingestions should result in vomiting.
IMPORTANT: Contact Your Vet First
Contact your veterinarian or Pet Poison Helpline (855-764-7661) BEFORE inducing vomiting. Not all ingestions should result in vomiting. This calculator helps calculate the correct dose IF your vet has directed you to induce vomiting at home.
ASPCA Animal Poison Control: 888-426-4435
When your dog eats something it should not have, the instinct is to act fast. Inducing vomiting at home with 3% hydrogen peroxide can be the right call — but only in the right circumstances. This calculator helps you determine both whether it is safe to induce vomiting and exactly how much hydrogen peroxide to use based on your dog's weight.
When to Induce Vomiting in Dogs — and When NOT To
Vomiting induction is appropriate when a dog has recently ingested a toxic substance that can be safely retrieved from the stomach. The key word is "recently" — most veterinary toxicologists recommend acting within 2 hours of ingestion, while the stomach is still likely to contain the substance.
However, vomiting should never be induced without first considering whether the substance ingested is safe to bring back up. Several categories of substances are more dangerous coming back up than staying down:
- Corrosive substances (bleach, drain cleaner, oven cleaner, battery acid): These cause chemical burns on the way down — bringing them back up through the esophagus doubles the exposure and can cause severe esophageal damage.
- Petroleum products (gasoline, motor oil, kerosene, lighter fluid): High aspiration risk — even a small amount inhaled into the lungs can cause aspiration pneumonia.
- Sharp objects (bone shards, broken glass, metal): Can lacerate the esophagus on the way back up.
- Expanding substances (some types of foam): May block the airway when vomited.
When in doubt about what was ingested, call the Pet Poison Helpline (855-764-7661) before taking any action.
Why Only 3% Hydrogen Peroxide
The 3% concentration is the only safe choice for dogs. Here is why concentration matters critically:
- 3% (pharmacy grade): Safe and effective for inducing vomiting. Creates bubbling action in the stomach that triggers the vomiting reflex.
- 6% (hair developer): Can cause hemorrhagic gastroenteritis — bloody diarrhea, bloody vomiting, severe GI damage.
- 10–30% (food grade or industrial): Can cause severe tissue damage, internal burns, and is potentially fatal.
The standard 3% hydrogen peroxide is the brown bottle sold in the first aid aisle of any pharmacy, typically labeled "USP Hydrogen Peroxide 3%." Check the expiration date — hydrogen peroxide degrades over time and an old bottle may not be potent enough to work effectively.
Step-by-Step: How to Induce Vomiting at Home (Vet-Approved)
- Call your vet or Pet Poison Helpline first — confirm that vomiting is appropriate for what your dog ate.
- Use this calculator to confirm the correct dose (1 ml per lb, max 45 ml).
- Draw up the dose in an oral syringe — do not guess with a tablespoon, as precision matters for small dogs.
- Administer toward the back of the cheek pouch (the space between the cheek and the back teeth). Do not squirt directly down the throat.
- Walk your dog gently or slowly rock it from side to side to help mix the hydrogen peroxide with stomach contents.
- Wait 10–15 minutes. Most dogs vomit within this window.
- If no vomiting after 15 minutes: give one repeat dose of the same amount.
- If still no vomiting after 2 doses: go to the vet. Do not give more hydrogen peroxide.
- After vomiting: keep the dog still and monitor breathing. Collect a small vomit sample if possible.
- Call your vet to confirm next steps — they may recommend activated charcoal, supportive care, or an exam.
What to Do After Your Dog Vomits
Post-vomiting care is often overlooked but equally important:
- Keep the dog calm and still — do not allow vigorous activity for at least 30 minutes
- Monitor breathing — if there is any coughing, gagging, or respiratory distress, go to an emergency vet immediately (possible aspiration)
- Withhold food for 2–4 hours; offer small amounts of water after 30 minutes if the dog is alert
- Do not give another dose of hydrogen peroxide — the stomach lining is irritated and re-dosing increases the risk of hemorrhagic gastroenteritis
- Call your vet to report what was retrieved in the vomit and what the dog's current status is
- If you are unsure whether all of the ingested substance was retrieved, your vet may want to perform x-rays or run blood work
Substances Where You Should NEVER Induce Vomiting
Corrosives and Caustics
- Bleach and chlorine products
- Drain cleaners (Drano, Liquid-Plumr)
- Oven cleaners
- Battery acid
- Strong acids or alkalis
Petroleum Products
- Gasoline and motor fuels
- Motor oil
- Kerosene and lamp oil
- Lighter fluid
- Paint thinner and solvents
Physical Hazards
- Bone shards (cooked bones)
- Broken glass or ceramics
- Nails, screws, or metal pieces
- Long linear objects (strings, rubber bands)
Medical Conditions — Do Not Induce
- Dog is unconscious or seizing
- Dog is already vomiting
- Dog is severely lethargic or in shock
- Dog has a known megaesophagus
- Brachycephalic breeds — vet guidance required
Frequently Asked Questions
How quickly does hydrogen peroxide work to make a dog vomit?
Most dogs vomit within 10–15 minutes of receiving the correct dose. Gently walking the dog after administration speeds this up by mixing the solution with stomach contents.
What is the maximum dose of hydrogen peroxide for a dog?
The maximum dose is 45 ml (about 3 tablespoons or 9 teaspoons), regardless of how large the dog is. Giving more than 45 ml does not increase effectiveness and increases the risk of gastric hemorrhage and aspiration.
Is hydrogen peroxide safe for dogs?
At 3% concentration and at the correct dose, hydrogen peroxide is an accepted method for inducing vomiting in dogs as recommended by veterinary toxicologists. However, it can cause gastric hemorrhage if overdosed or if repeated too many times. It should only be used when a vet has directed you to do so.
Can I use hydrogen peroxide if my dog ate something more than 2 hours ago?
After 2 hours, most of the stomach contents have moved into the small intestine, making vomiting induction largely ineffective. Call your vet — they may recommend activated charcoal or other interventions that work further along the GI tract.
Why is hydrogen peroxide safe for dogs but not cats?
Dogs and cats have different physiological responses to hydrogen peroxide. In cats, hydrogen peroxide can cause hemorrhagic gastroenteritis and is not reliably effective at inducing vomiting. Vets use a different medication (dexmedetomidine, given by injection) to induce vomiting in cats.
What if I gave too much hydrogen peroxide?
If you accidentally gave more than the recommended dose, contact your vet or Pet Poison Helpline immediately. Signs of hydrogen peroxide overdose include bloody vomiting, extreme lethargy, and bloating. Do not induce additional vomiting.
What does the vet use to induce vomiting?
Veterinarians use apomorphine (given by injection or conjunctival application) or, more recently, dexmedetomidine. These are far more reliable and carry fewer risks than hydrogen peroxide. If you can get to a vet quickly, this is always the preferred option.
Should I feed my dog before giving hydrogen peroxide?
A small amount of food (a few tablespoons) in the stomach can help — it gives the hydrogen peroxide something to mix with and can increase the effectiveness of vomiting. However, do not give a full meal. Ask your vet or poison helpline for guidance specific to your situation.
What about activated charcoal — when is that used instead?
Activated charcoal is used to adsorb toxins that have already passed into the intestines, or when vomiting induction is contraindicated. It is given orally and works by binding the toxin so it cannot be absorbed. It is most effective within a few hours of ingestion and is typically administered by a veterinarian.
Can I use salt to make my dog vomit?
No. Salt (sodium chloride) used in amounts sufficient to induce vomiting can cause salt poisoning (hypernatremia), which can be fatal. Do not use salt, mustard, or other home remedies. 3% hydrogen peroxide, when directed by a vet, is the only safe home method.
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A Final Word on Acting Fast
The 2-hour window is real — and it narrows faster than most people expect. The moment you realize your dog has eaten something potentially dangerous, your first call should be to your vet or Pet Poison Helpline, not to a search engine. These services exist precisely for this situation and can tell you within minutes whether you need to induce vomiting, rush to a vet, or simply monitor.
This calculator is designed to give you the correct dose if you have already received guidance to proceed. It is a tool for prepared dog owners, not a substitute for expert advice in an emergency.