Never the cocoa tin

The others worth knowing by heart

Xylitol is the one that surprises people. It is a sweetener in sugar-free gum, some peanut butters, mints and baked goods, and in dogs it can cause a sudden drop in blood sugar and liver failure. It is dangerous at very small amounts. Read the label on any peanut butter before it goes in a toy.

Grapes and raisins can cause kidney failure, and the frightening part is that nobody has pinned down a reliable safe dose — some dogs react to very little.

Onions, garlic, leeks and chives damage red blood cells, cooked or raw, and powdered forms are more concentrated than fresh.

Macadamia nuts, alcohol, and raw yeast dough all belong on the same list.

Keep the number somewhere findable

Put your vet's out-of-hours number and an animal poison control line in your phone before you need them. In the US the ASPCA Animal Poison Control Center runs 24 hours on (888) 426-4435 — there is a consultation fee, and it is worth it at two in the morning.

Open both tins. Hand over what belongs to whom. That is the entire safety protocol, and it works because the two halves were never in the same container.