Warning to prevent chocolate overdose in pets this Easter

As we look forward to indulging in the abundance of chocolate available this Easter, we need to make sure our pets do not have so much as a nibble.

"Because of their indiscriminate eating habits, Easter is one of the times we see a lot of dogs with chocolate intoxication. And other pets can be affected too." said emergency care vet Dr Sarah Haldane from the University of Melbourne Vet Clinic and Hospital.

"We encourage everyone to keep chocolate and baked goods containing chocolate out of reach of their pets".

Chocolate contains chemicals, such as caffeine and theobromine to which dogs are particularly sensitive. Theobromine is a naturally-occurring stimulant in the cocoa bean, used to make chocolate.

"The effects of theobromine and caffeine vary with the size of the dog and the form of chocolate, generally the darker or more bitter the chocolate the more toxic it is."

The ingestion of 50gm of dark chocolate per 5kg of a dog’s weight and of 200gm of milk chocolate per 5kg dog weight is in the danger zone. A 10kg dog could be poisoned by consuming just over 50g of dark chocolate or 500g of milk chocolate.

"In the clinic, we recently treated Max the dachshund for chocolate intoxication. He had an increased heart rate and was developing changes in his behaviour and mental state. He also had a long-standing problem with his heart, so we needed to be especially careful when treating him."

He was treated initially by his local vet and then came to our emergency centre for 24 hour care. He was sedated to calm him down and to stop tremors induced by chocolate. He was given activated charcoal to swallow and an enema to decrease absorption and facilitate removal of the chocolate from his intestines.

He was also treated with intravenous fluids and had a urinary catheter placed to stop toxic metabolites being reabsorbed from his urine. Max was greatly improved by the following day and went home within 24 hours of treatment.

"While humans can safely ingest big quantities of chocolate, dogs metabolize theobromine more slowly, which triggers chocolate poisoning." added Dr Haldane.

The chemicals in chocolate can also pass through the placenta and into the mother’s milk and affect pups.

"In humans, theobromine provokes the release of the euphoria hormone, serotonin but in dogs low doses trigger vomiting, nausea, increased urination or diarrhoea."

Cocoa powder is also a very toxic to dogs; so chocolate mud cake could be a real health risk for a small dog.

Chocolate tends to cause digestive upsets initially, as it is high in sugar and fat. Vomiting and diarrhoea are often the initial symptoms. Six to twelve hours later, the chemicals themselves start acting. They tend to have a diuretic effect, so the pet may urinate more than usual and become thirsty. Pets often become agitated and excitable and start pacing.

More dangerous symptoms can then develop, including an elevated, sometimes irregular heart rate, blood pressure changes and epileptic-type seizures. These signs can last for up to three days if untreated, and can be fatal to the pet, with the heart or breathing giving out, especially with exercise. Any cases of suspected chocolate toxicity should be immediately reported to your vet. Prompt treatment will mean a much better prognosis.

"Your dog may need an examination of its nervous system and cardiac function. We may want to test the blood and urine concentration of sugar (glucose) and of the active ingredient in the chocolate. Since this poisoning progresses rapidly, signs may need to be treated symptomatically until a laboratory diagnosis is confirmed."

"If your dog is having a seizure, do not attempt to cause vomiting; take him or her to your veterinarian without delay. If the chocolate has just been consumed ring your vet for advice immediately."

"While we like to think of our pets as part of our family, it doesn’t mean they can eat what humans eat. The tiniest of pieces is not going to do any harm but it gives them a taste for it which can lead to problems for everyone."

(Source: Nerissa Hannink: University of Melbourne: March 2008)