Why are macadamia nuts bad for dogs?

Macadamia poisoning in dogs has been recognized for decades, yet researchers still do not know which compound is responsible. What is clear is that dogs can react to small amounts. No safe amount has been established, and the risk depends on the dog's size and how much it ate, so every exposure deserves a call.

Roasted, raw, salted and unsalted macadamias all carry the risk.

Signs usually start within 12 hours. The most distinctive is weakness in the hind legs, where the dog struggles to stand or walks unsteadily. Vomiting, tremors, stiffness, lethargy and a high temperature are also common. Some dogs seem in pain when touched.

With veterinary care, most dogs recover within 24 to 48 hours. The picture becomes more serious when macadamias are combined with chocolate, as in cookies or coated nuts, because chocolate brings its own toxicity. That is another reason to call early.

White chocolate and macadamia cookies, mixed nut bags, trail mix, granola, muesli bars, nut butters and cakes are common sources. Macadamia trees also grow in gardens in Australia, Hawaii and parts of the US, where dogs may eat fallen nuts.

Note your dog's weight, roughly how many nuts were eaten, whether chocolate was involved, and when. Keep the packaging. Do not try to make your dog vomit at home unless your vet tells you to.