CHOCOLATE, GRAPES AND RASINS.
As a form of poisoning, chocolate cannot be considered particularly common. Although it does affect many species, it is reported most commonly in dogs in which there appear to be individual susceptibilities.
Chocolate is made from the roasted seeds of the tropical cocoa plant, Theobroma cacao. The name gives a clue to the toxic principle. Theobromine is an alkaloid drug used as a diuretic, heart stimulant, vasodilator and smooth muscle relaxant. This gives some indication of its poisoning effects. The toxic principle is not only found within the seeds. Cocoa shells have recently appeared in supermarkets and garden centres as an alternative to bark as a mulching agent. Recently there was a report of a winning Weimaraner bitch that had died from eating this garden mulch.
The main problems occur due to over engorgement of chocolate. If a dog is going to be treated with the drug, Theobromine, the dose is usually around 20mg/kg. The fatal dose considered to around ten times that, 200mg/kg but a toxic dose i.e. that which can cause symptoms, is about 100mg/kg upwards. Milk chocolate contains 1.5-3mg Theobromine per gram. Thus a 25kg dog would have to consume over a kilo of milk chocolate before any toxic signs theoretically appeared. Nevertheless this is only five 200mg bars of Cadbury’s not excessive shopping in the run up to Christmas if you have hungry children/family members with a sweet tooth! Make sure the Xmas tree choc decorations are out of reach of any chocoholic dogs! Plus be extra cautious with the Easter eggs! Good quality dark chocolate can have up to 20mg/gm Theobromine as can cocoa powder. The same 25kg dog would only have to eat less than a 200 gm bar of expensive Belgian chocolate, or, for that matter cooking chocolate to start showing signs. Thus, the signs of mild chocolate poisoning may be far more common than we realise.
WHAT ARE THE SIGNS? Vomiting, diarrhoea, increased thirst and urination, general hyperactivity with occasional period of depression and seizures. Diagnosis is based on these symptoms and clinical examination. The abdomen can be tender with an increased irregular heartbeat. History is also important. Is the dog regularly fed chocolate or does the dog live in a household where chocolate is readily available.?
The treatment depends entirely upon the severity of the signs.:- If there is a history of choc ingestion well tried absorbents such as activated charcoal are administered. If there are nervous signs and an increased heart rate, tranquillisers or sedatives may be prescribed together with specific heart treatments if considered necessary. The patient is usually hospitalised and fluid therapy administered for at least 24 hrs. Thus, the entire situation is potentially serious even if the patient does not look that bad. It should be remembered that a significant percentage of dogs will die of chocolate poisoning showing no signs at all except sudden death which upon autopsy is found to be due to heart failure. What about doggy’s choccies you ask? The advice is the level of Theobromine is so low in these that they pose no risk but there are treats available with no Theobromine at all! Grapes and Raisin’s are also poison’s to dogs and can cause similar symptoms as chocolate.
