Happy Easter

Too much of a good thing?

Easter is just around the corner - already.

Chocolate is particularly attractive to dogs, and is in abundant supply at this time of the year, but large amounts can be highly toxic. Small dogs are particularly vulnerable, as the sorts of amounts needed to supply them with a high enough dose to be toxic are well within the normal amounts found around the house, especially at holiday times. Although, theoretically, the same applies to cats, in practice it is very rare for cats to even like chocolate, let alone eat the amounts that may induce toxicity.

What causes chocolate poisoning?

The drug that causes the toxicity is Theobromine, from a family of compounds called methylxanthines. Dogs cannot detoxify this compound at a fast enough rate.  Caffeine is also a member of this family of compounds.

How much is needed?

The table below shows the amounts of Theobromine that can be found in different types of chocolate products. By far the most Theobromine is found in dark chocolate, especially cooking chocolate, and almost none is found in white chocolate.

The LD50 of Theobromine in the dog (the dose level at which 50% of individuals are likely to die if exposed to it) is 250-500mg/kg body weight. Thus, as little as little as 7.5ozs of dark cooking chocolate could prove fatal to a 10kg (22lb) dog. It would take some 20ozs of normal dark chocolate to have the same effect. Milk chocolate is less toxic, and a lethal dose is unlikely unless amounts or 2-3lbs or more are ingested.

Although amounts less than these may not be lethal, they may induce clinical signs associated with theobromine toxicity. These may include vomiting, restlessness, hyperactivity, ataxia, muscle tremors, tachycardia (fast heart rate), cardiac arrhythmias, seizures, hyperthemia (high temperature), polydipsia/polyuria, cyanosis, and coma.

Needless to say, a few simple precautions to keep all chocolate out of the reach of dogs will mean that we all have a Happy Easter!