Chocolate may be a delicious, sweet treat for humans, but it’s highly toxic for dogs. 

Why is chocolate toxic for dogs? 

Chocolate contains both theobromine and caffeine which are toxic to dogs. Both these compounds are both stimulants that are well tolerated by humans, however, dogs’ digestive systems metabolise them much more slowly. Because of this, they can build up to toxic levels very rapidly. 

Your dog might have gotten away with sneaking a tiny bit of chocolate in the past, but don’t assume that means they’ll be okay next time. The amount of chocolate that causes toxicity varies with the size of the dog and the type of chocolate. The darker or more bitter the chocolate (e.g. baking chocolate and dark chocolate), the more theobromine and caffeine it contains and therefore the more toxic it is for your dog. Some forms of chocolate contain additional sweeteners (such as xylitol) which are also toxic to dogs. 

Can dogs eat white chocolate? 

While white chocolate has significantly lower levels of theobromine and caffeine than milk and dark chocolate, it is still high in fat and sugar which can also cause serious health issues if consumed in large amounts. It’s best to avoid all forms of chocolate entirely and stick to dog treats instead.  

What happens when dogs eat chocolate? 

Signs your dog is suffering from chocolate toxicity include: 

  • Vomiting 
  • Diarrhoea 
  • Increased thirst/urination 
  • Restlessness or agitation 
  • Rapid breathing/panting 
  • Increased heart rate 
  • Tremors 
  • Seizures 


The theobromine and caffeine in chocolate affect a dog’s digestive system, nervous system, heart, and kidneys. Symptoms of toxicity can start within a couple of hours of ingestion, but in some cases may take up to 12-24 hours. 

What to do when your dog eats chocolate 

If you know your dog has eaten chocolate or they’re showing signs of chocolate toxicity, contact your local veterinary clinic or emergency veterinary hospital immediately. 

Chocolate toxicity can be fatal. The earlier your vet can intervene and start supportive care the better the chance to minimise the risk of serious complications.