Chocolate and dogs don't mix!
It’s that time of the year to bestow the ones we love with cards and gifts as a way of letting them know just how much they are thought of and loved. This can quite often involve chocolate, and as much as we all love a bit of chocolate, this can be dangerous to our dogs if ingested.
The problem is that eating even a small piece of chocolate leads a dog to crave more and can mean they will literally jump at an opportunity to steal any type of chocolate.
Why is chocolate poisonous to dogs? Chocolate contains theobromine - a naturally occurring stimulant found in the cocoa bean. Theobromine increases urination and affects the central nervous system as well as heart muscle. While amounts vary by type of chocolate, it's the theobromine that is poisonous to dogs.
Symptoms of chocolate dog ingestion and toxicity. You can recognize that your dog has eaten a toxic dose of chocolate from the symptoms. Within the first few hours, the evidence will include vomiting, diarrhoea, hyperactivity and as time passes and there's increased absorption of the toxic substance, you'll see an increase in the dog's heart rate, which can cause arrhythmia, restlessness, hyperactivity, muscle twitching, increased urination and/or excessive panting. This can lead to hyperthermia, muscle tremors, seizures, coma and in some cases sadly death.
Knowing how much is too much for each dog is a difficult question, but ultimately, it’s down to the level of cocoa in the chocolate. Generally, the darker the chocolate, the higher the cocoa content.
As a guide, here’s a list of the quantities of chocolate type that can be toxic to dogs:
Milk chocolate - approximately 500g of milk chocolate is poisonous to a 10kg dog. The average chocolate bar contains 56g to 85g of milk chocolate. It would take 2-3 chocolate bars to poison a 5kg dog. Semi-sweet chocolate has a similar toxic level.
Dark chocolate - 150g of dark chocolate is toxic to a 10kg dog; 90g for a 5kg dog.
Baking chocolate - two squares of 28g baking chocolate is toxic to a 10kg dog; one square of 28g for a 5kg dog.
So, if you are lucky enough to receive some yummy chocolate, make sure it is safely out of your dog’s reach! If you do suspect your dog has ingested some, you should contact your vet immediately for advice.
Chris Devlin BVSc MRCVS is a Vet and Partner at Hillside Veterinary Centre in Corfe Mullen.