My Dog Ate Chocolate — What to Do Right Now

Step 1 — Act Immediately

Call your vet right now, even if your dog appears well. Theobromine toxicity can take 6–12 hours to produce obvious symptoms — by which point treatment is much harder than if started early. If your vet's surgery is closed, call the out-of-hours emergency line immediately.

Have this information ready: your dog's weight (in kg), the type of chocolate eaten (dark, milk, white, or cocoa powder), the approximate amount eaten (in grams if possible — check the wrapper), and when they ate it. This information allows your vet or the Animal Poison Line (01202 509 000) to calculate the dose and advise on urgency.

Step 2 — Understanding the Risk

Not all chocolate carries the same risk. Approximate theobromine content per 100g: dark chocolate (70%+) ~600–700 mg; milk chocolate ~150–200 mg; white chocolate ~2–5 mg; cocoa powder ~2,000 mg.

As a rough guide, toxic symptoms begin around 20 mg of theobromine per kg body weight; serious cardiac effects at higher doses. A 5 kg dog (e.g. a small terrier) could be affected by 25–50g of dark chocolate or 100–150g of milk chocolate. A 30 kg Labrador would need substantially more before serious effects, but no dose should be considered safe without veterinary assessment.

Your vet will use a theobromine dose calculator to determine whether the amount eaten is likely to require treatment.

Step 3 — Symptoms to Watch For

Early signs (6–12 hours after ingestion): vomiting, diarrhoea, restlessness, excessive thirst, and frequent urination.

More serious signs (12+ hours): rapid or irregular heart rate, muscle tremors, rigid muscles, very high body temperature, and seizures. Older dogs and those with heart conditions are at greater risk of severe cardiac effects.

If your dog begins showing muscle tremors, irregular breathing, or collapse, this is an emergency — go to the nearest veterinary practice immediately, do not wait for a phone consultation.

Treatment and What to Expect

If treatment is advised, your vet may induce vomiting (most effective within 1–2 hours of ingestion) and administer activated charcoal to prevent further absorption. For moderate or severe exposures, intravenous fluid support, medication to manage heart rate, and anti-seizure drugs may be used. There is no antidote for theobromine; treatment is supportive.

The prognosis for chocolate toxicity is generally good with prompt treatment. Deaths are uncommon when treatment is sought quickly. Most dogs recover fully within 24–48 hours with appropriate care.