Chocolate and other household toxins in Hong Kong homes

Most poisoning calls I take start the same way: a packet on the floor, a guilty-looking dog, and an owner trying to work out whether this is a wait-and-see or a get-in-the-taxi-now situation. The honest answer is that it depends almost entirely on dose.

Chocolate is the classic example. The toxic component is theobromine, and its concentration varies enormously — white chocolate is essentially harmless, milk chocolate is a mild risk at typical snack sizes, and 85% dark or baking chocolate can cause tremors and dangerous heart rhythms in a small dog after only a few squares.

Grapes and raisins deserve special mention because there is no reliable safe dose. Idiosyncratic acute kidney injury has been reported after very small ingestions, so any amount warrants a call.

Xylitol (often labelled 'birch sugar') in sugar-free gum, peanut butter and some supplements causes a rapid insulin surge and profound hypoglycaemia in dogs within 30 minutes. This is a genuine emergency.

Lilies deserve their reputation with cats: every part of the plant, including pollen brushed onto fur, can cause fatal kidney injury. If you have a cat, keep lilies out of the flat entirely.

What to do in the first ten minutes: take the packaging with you, estimate the amount and the time, and call your vet before doing anything else. Do not induce vomiting at home — hydrogen peroxide and salt cause more harm than the toxin in many of the cases I see.

You can use the Toxicity Calculator on this site to get a rough risk band while you are on the phone. It is a triage aid, not a diagnosis.