The wrapper is shredded, the dog looks proud of itself, and you have about thirty seconds of panic before you need a plan. Start here: figure out the dose, decide who to call, and know what the next twelve hours look like. Most chocolate raids end fine. The ones that don't are usually dark chocolate, small dogs, or both.
Chocolate's danger to dogs is theobromine, a caffeine-relative stimulant that dogs clear extremely slowly. Everything comes down to dose: milligrams of theobromine per kilogram of dog. Multiplying ounces eaten by the chocolate type's theobromine content and dividing by weight in kilograms gets you the number a vet will want anyway.
| Chocolate | Theobromine | A 20-lb dog would need to eat (typical) |
|---|---|---|
| White | ~0.25 mg/oz | ~726 oz (not a real risk) |
| Milk | 44–58 mg/oz | ~3.6 oz to reach 20 mg/kg |
| Semisweet / dark | 135–160 mg/oz | ~1.2 oz to reach 20 mg/kg |
| Unsweetened baking | 390–450 mg/oz | ~0.4 oz to reach 20 mg/kg |
| Cocoa powder | 400–737 mg/oz | ~0.3 oz to reach 20 mg/kg |
Read that last row again the next time a brownie pan gets licked: cocoa powder is the most concentrated chocolate product in a kitchen, and half a cup of it is a genuine emergency for a mid-size dog.
Weight, chocolate type, amount — the calculator returns the mg/kg dose range and the severity band, using published Merck and ASPCA theobromine values.
Chocolate Toxicity Calculator →Under 20 mg/kg, most dogs get away with an upset stomach: the fat and sugar cause vomiting or diarrhea even when the theobromine itself doesn't. From 20 to 40 mg/kg, expect real theobromine effects, restlessness, thirst, vomiting, pacing. At 40 to 60 mg/kg, hearts race and tremors start. Above 60 mg/kg, seizures and arrhythmias enter the picture, and the estimated lethal range for theobromine in dogs sits around 100 to 200 mg/kg.
Two situational multipliers worth knowing. Small dogs hit every band sooner: a chihuahua and a lab eating the same bar live in different dose universes. And older dogs or those with heart conditions can run into trouble at doses that would only mildly bother a healthy adult.
Theobromine's slow metabolism means symptoms usually take 6 to 12 hours to appear, and they can persist for days. That gap is the trap: a dog that seems fine at hour two is not cleared, it's pre-symptomatic.
If your dog has any existing symptoms and you know chocolate went missing, skip the calculator and go straight to the phone.
Your regular vet during office hours is the cheapest and fastest first call; they know your dog's history and can induce vomiting if the timing is right. After hours, two national lines run around the clock: ASPCA Animal Poison Control at (888) 426-4435 and Pet Poison Helpline at (855) 764-7661. Both charge consultation fees, and both are worth it: they'll triage the dose, tell you whether to watch or come in, and if it's the latter, call ahead to the emergency clinic so treatment starts on arrival.
Have four things ready: what kind of chocolate (the wrapper's cacao percentage is gold), roughly how much is missing, your dog's weight, and when the raid happened. The wrapper math is fast: a standard milk chocolate bar is about 1.55 oz, one baking square is half an ounce, a typical chip bag is 10-12 oz.
Don't induce vomiting yourself unless a professional tells you to. Hydrogen peroxide dosing is weight-critical, aspiration pneumonia is a real complication, and vomiting can be contraindicated for other reasons. Don't try to wait it out above 20 mg/kg because the dog "seems fine" at hour three. And don't bother with milk, salt, or any internet folk remedy; none of them touch theobromine. What actually works is getting the chocolate out early or binding what's absorbed, both vet procedures.
Early in the window, the visit often runs to induced vomiting, sometimes followed by a dose of activated charcoal to bind remaining theobromine, and you're home by dinner. Moderate-to-severe doses mean IV fluids, an ECG to watch the heart, and medication if tremors or seizures develop, which can mean an overnight stay. Dogs treated promptly have good outcomes across the board; the expensive cases are the ones that waited. If you're wondering whether the visit is worth it financially, our vet visit cost tool breaks down typical routine and emergency pricing.
Usually yes, especially for milk chocolate and bigger dogs. Most cases involve doses under 20 mg/kg, which cause vomiting and diarrhea at worst. The danger climbs fast with darker chocolate and smaller dogs: 2 oz of baking chocolate puts a 20-lb dog near the estimated lethal range. Run the numbers, then call a vet with them in hand.
Multiply the ounces eaten by the chocolate's theobromine content (44-58 mg/oz for milk, 135-160 for semisweet and dark, 390-450 for baking, 400-737 for cocoa powder), then divide by your dog's weight in kilograms. Wrapper math gets you the ounces: a standard milk chocolate bar is about 1.55 oz, one baking square half an ounce, a chip bag 10-12 oz.
If the calculated dose is well under 20 mg/kg, watching at home is often reasonable, with your vet's blessing. Above 20 mg/kg, waiting is a bad plan: symptoms take 6-12 hours to show, theobromine clears slowly, and treatment works best before absorption peaks. The middle of the night is when most chocolate emergencies happen, and poison lines run 24/7.
Within the first couple of hours, often inducing vomiting, sometimes followed by activated charcoal to bind what's left. Sicker dogs get IV fluids, heart-rhythm monitoring, and medication for tremors or seizures. Most dogs treated promptly go home the same day or the next; the bill depends on whether it's an office visit or overnight emergency care.