What plants and household items are actually dangerous to pets?

A specific and knowable list — and the important point is that the dangerous items are frequently ordinary things, not obviously toxic chemicals, which is why poisoning cases so often involve kitchens and gardens rather than sheds.

Foods that are genuinely dangerous:

Grapes, raisins, sultanas and currants, which can cause kidney failure in dogs at unpredictable doses — there is no known safe amount, and this is the one most people underestimate. Mince pies and Christmas cake are common causes.

Xylitol, a sweetener in sugar-free gum, some peanut butters, toothpaste and baked goods. It causes a rapid, severe drop in blood sugar in dogs and liver failure. Extremely dangerous in small amounts.

Onions, garlic, leeks and chives, in any form including powdered and cooked, causing damage to red blood cells — cats are especially sensitive.

Chocolate, with dark and cooking chocolate far more dangerous than milk.

Macadamia nuts, and alcohol.

Cooked bones, which splinter.

Plants — the ones that matter most:

Lilies are lethal to cats. All parts, including pollen, and even brushing against one and grooming it off can cause fatal kidney failure. True lilies and daylilies should not be in a house with a cat.

Spring bulbs — daffodils, tulips, hyacinths — with bulbs more toxic than flowers.

Yew, oleander, foxglove and lily of the valley, affecting the heart.

Sago palm, severely toxic.

Household items:

Antifreeze (ethylene glycol), which is sweet-tasting and lethal in tiny amounts — cats are frequently poisoned via spills and leaking vehicles. Treatment is time-critical to the hour.

Rodenticides and slug pellets.

Human medicines — paracetamol is fatal to cats, and ibuprofen dangerous to both.

Permethrin flea treatments for dogs, applied to cats, which is a common and frequently fatal error.

Batteries, and liquid potpourri.

If you suspect poisoning: phone a vet immediately, take the packaging, and do not induce vomiting unless told to — for some substances it causes further damage.

General information, not veterinary advice.