Easter Eggs used to be a tightly focused seasonal treat: they arrived in the shops in the week before Easter, we bought them for our children on Easter weekend, and they were eaten on Easter Sunday. It’s different now: Easter Eggs are on sale as early as January, and they are piled high, on special offer in supermarkets from early March onwards. We have become used to eating chocolate eggs for a full month before Easter.
Chocolate manufacturers must be delighted with this marketing success, but as a vet, I’m very aware that the increased Easter Egg sales mean that there is an increased risk of problems for dogs. The main issue is that chocolate is toxic to dogs, and the more chocolate there is around the home, the higher the chance that dogs will accidentally eat a poisonous dose of chocolate.
Chocolate toxicity in dogs is widely misunderstood, and there are seven key points that should be common knowledge.
1. The basic fact is that chocolate contains a stimulant called theobromine. This is well tolerated by humans, giving us a mildly euphoric buzz, which is one of the reasons why chocolate is such a popular human treat. Dogs cannot metabolize theobromine as efficiently as humans, and blood levels rapidly rise after a small amount of chocolate has been eaten. High levels of theobromine interfere with the functioning of the heart muscle, leading to an irregular beat, leading on to outright heart failure. As a vet in practice, I see at least one dog every year dying of chocolate poisoning. This is not a theoretical risk: it’s a real life hazard.
2. Different types of chocolate contain higher or lower quantities of theobromine: the darker the chocolate, the higher the concentration. Plain, dark chocolate contains the highest levels, milk chocolate contains middling levels, while white chocolate contains no theobromine at all. And there are many “chocolate-flavoured” treats that contain no chocolate at all, and therefore no theobromine. The risk to a dog depends on how much of what type of chocolate has been eaten. If you are worried after your dog has eaten chocolate, take a photo of the packaging and ingredients, so that you can show the vet precisely what your dog has ingested.
3. It’s wrong to assume that it’s safe to give dogs small amounts of chocolate as treats. While it’s true that tiny amounts of chocolate will not directly poison dogs, the problem with doing this is that it teaches dogs to adore the taste, making it more likely that they will seek out chocolate if it is ever remotely within their reach. Dogs have such a sensitive sense of smell that if they have been primed with a desire for chocolate, they are able to find it and eat it in surprising situations.
4. The other big difference between dogs and humans when it comes to chocolate is that they do not have an “off switch” when it comes to chocolate consumption. If you or I were presented with a large box of chocolates, we might eat four or five chocolates before deciding that we had had enough. Dogs know no such inhibition: they love chocolate so much that they keep eating until every last crumb has gone. This savage appetite for chocolate means that if a dog finds a chocolate stash of any kind, they will likely consume the entire amount.
5. The toxicity of chocolate is dose related and predictable: in other words, it’s easy to work out when a dog has eaten a toxic amount. Small dogs are most at risk, because a relatively small amount of chocolate is dangerous. As an example, the fatal dose for a small terrier weighing 6kg would be just 50g (two ounces) of dark chocolate, or 100g (four ounces) of milk chocolate, which is just one small Easter Egg. In contrast, a 30kg Labrador would need to eat five small milk chocolate Easter Eggs to be at serious risk. The practical reality of the availability of chocolate around the home means that small dogs are most at risk of chocolate poisoning.
6. When a dog has been known to eat chocolate, the three important facts are what type of chocolate was it, how much was consumed, and what does the dog weigh. Chocolate poisoning calculators are widely available online (eg at petfixclub.com), and by entering the type and quantity of chocolate, followed by the dog’s weight, it’s easy to work out if the dog is at risk. If you do not have access to the internet, or if you do not have all of the necessary information, it’s safest simply to call your local vet (or the vet-on-call if it’s after-hours) immediately, or use an online vet messaging service, such as Petfixclub.com.
7. If there is a suspicion that the dog has eaten a toxic amount, it’s critically important to arrange to see your vet at once. If a dog is forced to vomit within an hour, the chocolate will be removed from the stomach before it has been absorbed into the bloodstream, averting the crisis. Vets have access to a handy injection which immediately and safely induces vomiting. Some people decide to “wait and see what happens”, but this is a dangerous approach: by the time a dog starts to show signs of being unwell, a toxic level of theobromine is already in the bloodstream, and nothing can be done to stop its dangerous impact on heart function. There’s a high risk of death if sufficient chocolate has been eaten.