Chocolate contains a stimulant called theobromine (a bit like caffeine) that is poisonous to dogs. The amount of theobromine differs in the different types of chocolate. Dark chocolate was previously reported to have the highest levels of theobromine, however, many brands are now injecting added theobromine into their milk and white chocolate. This means that milk and white chocolate can now pose the same danger level to our dogs as dark chocolate.
What does theobromine do and what symptoms will I see?
Theobromine mainly affects the heart, central nervous system and kidneys. Symptoms will occur from 4-24 hours after your dog has eaten chocolate and will vary depending on the amount of chocolate (theobromine) your dog has eaten.
If your dog has eaten chocolate, you may see:
- Vomiting (may include blood)
- Restlessness and hyperactivity
- Rapid breathing
- Muscle tension, incoordination
- Increased heart rate
How much chocolate is too much for my dog?
Our advice is not to give any chocolate to your dog, but if they have managed to get hold of some chocolate these are some guidelines you need to be aware of.
Theobromine doses in the region of 100-150 mg/kg bodyweight are toxic to dogs.
Approximate amount of theobromine in 25grams of chocolate.
- White chocolate can vary greatly in the amount of theobromine it contains. Although not naturally present, many brands inject theobromine into their white chocolate meaning it could actually contain as much theobromine as milk or dark chocolate.
- Milk chocolate generally contains 44-64 mg theobromine. However, some brands are now injecting higher levels of the ingredient into their milk chocolate.
- Semi-sweet chocolate and sweet dark chocolate contains 150-160 mg theobromine
- Unsweetened (baking) chocolate 390-450 mg theobromine
- Dry cocoa powder 800 mg theobromine
This means that for a Labrador (around 30kg bodyweight) we would expect to see a fatal toxic reaction if they had eaten ½kg dark chocolate or 170grams of baking chocolate. For milk and white chocolate this would depend on how much theobromine has been added to the chocolate.
Signs of poisoning will be seen at lower levels of ingestion. For example, a 30kg dog that has eaten 200g milk chocolate (if no additional theobromine has been added to the chocolate) is likely to have a digestive upset (vomiting and diarrhoea). If they had eaten 500g milk chocolate, it is likely that cardiovascular problems will be seen (increased heart rate) and if they had eaten 750g milk chocolate they may develop seizures.
It can be hard to tell exactly how much your dog may have eaten and the amount of caffeine and theobromine in chocolate will vary due to growing conditions, cocoa bean sources and variety. It’s always best to err on the side of caution and contact your vet for advice if you are at all concerned.
What should I do if my dog has eaten chocolate?
If you think your dog has eaten chocolate please contact your vet immediately, or find your nearest Vets Now Pet Emergency Clinic here.
Treatment may be needed if your dog eats any chocolate so please contact your vet as soon as possible. It will assist your vet if you can tell them how much chocolate your dog has eaten, what type of chocolate it was (wrappers can be very helpful) and when your dog ate the chocolate. This will enable them to work out whether your dog has eaten a toxic dose or not and what treatment your dog is likely to need.
There is no antidote to theobromine. In most cases your vet will make your dog vomit. They may wash out the stomach and feed activated charcoal which will absorb any theobromine left in the intestine. Other treatments will depend on the signs your dog is showing. They may need intravenous fluids (a drip), medication to control heart rate, blood pressure and seizure activity.
With prompt intervention and treatment even in dogs that have eaten large amounts of chocolate the prognosis for a poisoned dog is usually good.
Vets Now assumes no liability for the content of this page. This advice is not a substitute for a proper consultation with a vet and is only intended as a guide. Please contact your local veterinary practice for advice or treatment immediately if you are worried about your pet’s health – even if they are closed, they will always have an out of hours service available.