Case of the month: Barney's After 8 Encounter

Posted by Vetcall on 10 June 2013

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Reason for visit:

barneyBarney is a 5 year old 4.5 kg male neutered Poochon.  His owners arrived home after being out for the day to find Barney abnormally hyped up and restless.  He had urinated and defecated in the house and the wrappers of a bag of After 8 after dinner mint chocolates were strewn all over the lounge floor.  His owners were aware that chocolate can be toxic to dogs and immediately phoned the clinic for advice.


By a process of deduction we were able to work out that Barney had eaten about three quarters of the 134g bag so roughly 100g of chocolates.  We then estimated that the chocolates were about two thirds chocolate and one third mint filling. So this meant Barney had consumed about 67g of dark chocolate.  The toxic dose of dark chocolate for a dog of Barney’s size is about 19.5g and the LD50 (the dose which if consumed 50% of dogs would die) is 195.8g. Having consumed about 3x the toxic dose Barneys owners were told to bring him straight down to the clinic for emergency treatment.


On examination Barney was hyper excitable and had an elevated heart rate and temperature. The fur around his mouth was also very chocolaty!


Even though we had no idea when during the day Barney had eaten the chocolates we decided the best thing was to make him sick just in case he still had some left in his stomach. Barney was given Apomoprhine and within a few minutes he had brought up several chocolate wrappers, his partially digested breakfast and some chocolaty looking fluid. He was then given a dose of Activated Charcoal Solution orally to help bind the chocolate toxins in his gastrointestinal tract. By now Barney was looking very sorry for himself.  He was still feeling the effects of the Apomorphine and had black charcoal residue all over his face.  He was given an injection to help combat his nausea and because he was in a stable condition he was sent home for close observation overnight by his owners with instructions to take him immediately to the After Hours Centre if he showed any signs of deterioration.


When we phoned for an update the next morning Barney was back to his usual self. We recommended that Barney be fed Hills i/d canned food for a few days as it is easily digested and absorbed and then to transition him gradually back onto his normal food.

Barney’s story clearly illustrates how little chocolate (especially dark chocolate) is required to cause toxicity.

Why is chocolate toxic?

Chocolate is made from the fruit (beans) of the cacao tree. Theobromine, a component of chocolate, is a toxic compound in chocolate. Caffeine is also present in chocolate and a toxic component, but in much smaller amounts than Theobromine.  Dogs are the most common victims of Theobromine poisoning because as we all know they have a great sense of smell making it fairly easy for them to find any chocolate that it is left within their reach.  The toxic dose for cats is even lower than for dogs. However, cats are less prone to eating chocolate as they are unable to taste sweetness.  Unsweetened dark chocolate contains 8-10 times the amount of Theobromine as milk chocolate. Semi-sweet chocolate falls roughly in between the two for Theobromine content. White chocolate contains Theobromine, but in such small amounts that Theobromine poisoning is unlikely.

Symptoms of toxicity:

The symptoms of chocolate toxicity include vomiting, diarrhoea, hyperactivity, restlessness, excessive urination, muscle tremors and rigidity, effects on the heart rate and rhythm, high temperature, seizures, coma and death.  Vomiting and diarrhoea can occur 2-4 hours after intake. Advanced signs (seizures, heart failure, coma and death can occur 12-36 hours after intake).

Treatment of toxicity:

There is no antidote for chocolate toxicity. Treatment is purely supportive and includes inducing vomiting if the dog has eaten the chocolate in the last few hours to help try and get it out of the stomach, administering activated charcoal solution to help bind the toxins in the gastrointestinal tract, controlling nausea and feeding of a bland easily digested diet. In more serious cases intravenous fluid therapy, sedatives, seizure medication, oxygen and heart medication may be required.


Most dogs usually recover with aggressive supportive therapy.  If treatment is given within four hours of the chocolate being eaten the prognosis is good. Heart failure, weakness, seizures, coma and death can occur 12-36 hours after eating and the prognosis may be guarded.

Take home message:

It is important to remember to keep chocolates, chocolate cakes and chocolate coated goodies safely away from your pets!  If you think your pet has got into your chocolate stash then get them to a vet immediately.