Chocolate poisoning in dogs and cats
Toxic agent: Theobromine and caffeine (methylxanthines) · Reviewed 2026-08-18
Phone a vet now, before reading on. Have ready: your pet's weight, roughly how much was eaten and when, and the packaging if there is any. ASPCA Animal Poison Control (+1 888 426 4435), Pet Poison Helpline, or Animal PoisonLine in the UK.
Yes, chocolate is genuinely dangerous to dogs and cats, and the type matters more than most owners expect — a small bar of baking chocolate carries more theobromine than a large bar of milk chocolate.
What it actually does
Theobromine and caffeine block adenosine receptors and raise intracellular calcium, which overstimulates the heart and central nervous system. Dogs clear theobromine far more slowly than people do — the half-life is roughly 17 hours — so it accumulates instead of passing through, which is why a dose that would be trivial for a human matters for a dog.
How much matters
Risk tracks milligrams of theobromine per kilogram of body weight, so the same weight of chocolate is a different problem depending on what kind it is:
| Cocoa powder | ~26 mg theobromine per gram |
|---|---|
| Baking / unsweetened | ~16 mg/g |
| Dark (70%+) | ~5.5 mg/g |
| Milk chocolate | ~2 mg/g |
| White chocolate | negligible theobromine, but the fat and sugar can still cause pancreatitis |
Clinically, signs tend to begin around 20 mg/kg, cardiac effects around 40–50 mg/kg, and seizures around 60 mg/kg. Do not use these to decide whether to call — use them to understand why the vet asks for the pet's weight, the type of chocolate and the amount eaten.
What you will see, and when
Onset: 6 to 12 hours, occasionally sooner with cocoa powder or espresso-based products. Typical course: Up to 72 hours, because of the slow clearance.
- First hoursVomiting, diarrhoea, thirst, restlessness, a distended abdomen
- 6–12 hoursPanting, pacing, tremors, a racing heart, high blood pressure
- 12+ hoursArrhythmias, hyperthermia, seizures, collapse
What the vet will do
There is no antidote. A vet may induce vomiting if the ingestion is recent, give repeated doses of activated charcoal because theobromine is reabsorbed from the gut, and support the animal with IV fluids, anti-arrhythmics and anticonvulsants as needed. Monitoring is usually measured in days rather than hours.
Outlook
Good with early treatment. Most deaths involve large amounts of dark or baking chocolate in small dogs, or a delay of many hours before anyone realised.
Dogs and cats are not the same here
Cats are more sensitive per kilogram but rarely eat chocolate voluntarily — they lack sweet taste receptors. Most feline cases involve chocolate baked into something fatty.
Where it comes from in a normal house
- Baking chocolate and cocoa powder
- Chocolate cake, brownies and cookies
- Chocolate-covered raisins, which combine two separate toxins
- Cocoa mulch in gardens
- Advent calendars and Easter eggs left within reach
The thing people get wrong
“White chocolate is safe.”
It is close to theobromine-free, so it will not cause methylxanthine poisoning — but it is largely fat and sugar, and a dog that eats a lot of it can still develop pancreatitis. 'Not this poisoning' is not the same as 'safe'.
PawLife keeps your pet's weight, medication and feeding history in one place, so when you make this call you can answer the vet's questions in seconds. The full food safety database is free.
Get PawLife on the App StoreFrequently asked questions
How much Chocolate is dangerous?
Clinically, signs tend to begin around 20 mg/kg, cardiac effects around 40–50 mg/kg, and seizures around 60 mg/kg. Do not use these to decide whether to call — use them to understand why the vet asks for the pet's weight, the type of chocolate and the amount eaten.
How long after exposure to Chocolate do symptoms start?
6 to 12 hours, occasionally sooner with cocoa powder or espresso-based products. Vomiting, diarrhoea, thirst, restlessness, a distended abdomen. Up to 72 hours, because of the slow clearance.
Is Chocolate worse for cats or dogs?
Cats are more sensitive per kilogram but rarely eat chocolate voluntarily — they lack sweet taste receptors. Most feline cases involve chocolate baked into something fatty.
Is it true that: White chocolate is safe.
It is close to theobromine-free, so it will not cause methylxanthine poisoning — but it is largely fat and sugar, and a dog that eats a lot of it can still develop pancreatitis. 'Not this poisoning' is not the same as 'safe'.
Related emergencies
Sources
This page is information, not veterinary advice. Toxic doses vary with body weight, age, breed and individual sensitivity, and the figures above exist to explain what a vet is assessing, never to decide that an amount is safe. If you are reading this because something has already been eaten, call a vet.