Queensland Nut Poisoning in Dogs

The Queensland nut tree, also called macadamia, is native to Australia, specifically Queensland and New South Wales. It is cultivated for the nuts which are eaten raw or used to make cookies, candies, and other treats. Besides macadamia, other common names for Queensland nut include Hawaii nut, Australian nut, or Bush nut. These nuts are safe for human consumption, but they are toxic for dogs. The mechanism of toxicity is not known; symptoms are rarely noted in cats or other species.

Experimental studies have found that ingestion of Queensland nut at doses higher than 2.4 grams per kilogram of body weight causes vomiting, weakness, and tremors in dogs. Tremors and other muscular symptoms are especially noted in the hind legs. Symptoms of toxicity typically appear within 12 hours after ingestion and resolve themselves in 48 hours. Queensland nut poisoning is nonfatal, and most dogs recover even without treatment. Veterinary treatment can reduce absorption, avoid dehydration, and help to make your dog more comfortable. This is especially necessary if a large amount was ingested and symptoms are very severe. Many cookies or candies that contain Queensland nuts also have chocolate or raisins, foods that can be even more toxic for dogs. Several combined toxicities could be more serious or even fatal.

Queensland nut is another name for the macadamia nut, a common ingredient in cookies, candies, and trail-mix. These nuts can be safely consumed by humans, but they are toxic for dogs. Symptoms of Queensland nut poisoning are nonfatal and typically pass within 48 hours.

These are the symptoms you may see if your dog eats Queensland nuts.

• Vomiting
• Lack of muscle control
• Weakness
• Tremors
• Fever (hyperthermia)
• Depression

Types

Two types of macadamia can be cultivated to make Queensland Nuts. Both types could be toxic for your dog.

• Macadamia integrifolia – species used to produce nuts in the continental United States
• Macadamia tetraphylla – species cultivated in Hawaii and Australia

• Owners feeding Queensland nuts or macadamia nut cookies to dogs may not realize that severe symptoms can occur
• Dogs chewing open and eating a bag of nuts may consume a dangerous amount
• Dogs stealing cookies left out to cool could experience toxicities to more than one ingredient
• Small dogs are more at risk as their bodies may find processing the nut toxins difficult

Call a veterinarian or a poison helpline of your dog is showing unusual symptoms after eating products that contain Queensland nuts and/or other foods that could be toxic for dogs. Be ready with your dog’s weight and an estimate of how much you think was ingested. Don’t induce vomiting unless recommended by a professional. Follow the agent’s instructions exactly and get emergency in-person treatment if a large amount was ingested or there are severe symptoms.

If ingestion was recent, and amounts greater than 1 or 2 grams per kilogram of your dog’s weight were consumed, the veterinarian will induce vomiting. Activated charcoal is also typically given to reduce absorption. Other treatment will be symptomatic. Fluid administration can help to prevent dehydration from excessive vomiting. Medication may be given to reduce fever (antipyretics) and make dogs more comfortable. In severe cases, the veterinarian will keep your dog until symptoms have passed and the nuts are excreted from your dog’ system. Queensland nut poisoning combined with chocolate or raisin poisoning could require more aggressive treatment.

Most dogs will recover from Queensland nut poisoning without incident. Veterinary treatment could be indicated if a large amount was ingested or symptoms are severe, but dogs are still likely to recover. Queensland nut poisoning combined with another more serious toxicity could have a more guarded prognosis.

To manage the condition, avoid giving your dog cookies or any food that contains Queensland nuts. Don’t leave cookies out to cool where your dog can reach them and avoid open containers of nuts or trail-mix. Store nuts in a metal can or another dog proof container rather than a plastic bag that can easily be chewed through.