What nuts are toxic to dogs?

Macadamia nuts cause weakness, tremors and vomiting, often within 12 hours. Black walnuts and fallen or mouldy nuts of any kind can carry tremorgenic mycotoxins that cause tremors and seizures. Acorns contain tannins that can upset the gut and harm the kidneys. Conkers (horse chestnuts) contain aesculin and cause vomiting and restlessness.

Almonds and Brazil nuts are hard and can cause choking or blockages. Pecans and walnuts are prone to mould. Pistachios come in sharp shells and are often salted. Hazelnuts are the right size to choke a small dog. All of these are high in fat, which can cause stomach upset or pancreatitis.

Plain unsalted peanuts, cashews and cooked sweet chestnuts are not toxic and can be given in very small numbers. Pine nuts are soft and not toxic but very rich. Peanut butter without xylitol is a popular option in thin smears.

Remove shells, choose unsalted, and break nuts into small pieces. Three or four peanuts or one or two cashews is enough for a medium dog.

Salted, honey-roasted, chili and chocolate-covered nuts add their own problems. Mixed nuts and trail mix may hide macadamias or raisins. Always check the label before assuming a nut snack is harmless.

Even the safer nuts are 45 to 70 percent fat and dense in calories. Most dogs get more benefit from lower-fat treats like carrot, apple or blueberries.