Macadamia Nut and Other Nut Poisoning

ImmunityDiseasesMeongsiljang Veterinary Advisory Board

This guide outlines the signs of macadamia nut and other nut poisoning in pets, along with emergency response steps and the treatment and recovery process.

What Is Macadamia Nut and Other Nut Poisoning?

A dog gazing curiously at a bowl of nuts on the table

Macadamia nut and other nut poisoning is a dietary toxicity that occurs when dogs ingest macadamia nuts or other types of nuts. According to veterinary textbooks, macadamia nut poisoning has only been reported in dogs to date. Symptoms may include hind limb weakness, vomiting, hyperthermia, and muscle tremors, with most cases resolving spontaneously within 24 to 48 hours. However, if your dog has consumed macadamia products mixed with chocolate or ingested a large quantity, seek veterinary care immediately.

Causes: Which Nuts Are Dangerous and Why?

The exact toxic agent in macadamia nuts has not yet been identified. According to veterinary textbooks, clinical signs have been reported at doses as low as 0.7 g per kilogram of body weight, toxicity consistently occurs at doses exceeding 2.2 g/kg, and doses as high as 62.4 g/kg have been reported. In cases of naturally occurring poisoning, the median ingestion amount was 11.7 g/kg. The level of risk can vary depending on the type of nut and any processing or additives involved.

Macadamia nuts: The toxic mechanism remains unknown, but potential causes include components inherent to the nut itself, contaminants from the processing stage, or mycotoxins.

High-fat nuts (such as almonds and pecans): Macadamia nuts are very high in fat, containing approximately 75%. Consuming such high-fat foods can increase the risk of pancreatitis, so caution is advised.

Processed or mixed products (such as candies, cakes, and cookies): These are often consumed in forms that also contain chocolate, butter, or sugar, which can introduce additional risks.

Nut mixes (such as trail mix): Other ingredients included in the mix, such as grapes or raisins, can pose additional risks, so please always check the ingredient list carefully.

Checklist of Main Symptoms

The time it takes for symptoms to appear after ingesting macadamia nuts can vary from dog to dog. If you notice any of the following signs, check whether your dog has eaten any nuts.

Weakness in the hind legs: Stumbling while walking or dragging the hind legs

Vomiting: Repeated vomiting may occur shortly after ingestion

Hyperthermia: Abnormally high body temperature

Muscle tremors: Shaking or trembling throughout the body

Abdominal pain: Crying out or curling up when the belly is touched

Lethargy (CNS depression): Unusually limp and reluctant to move

A small dog lying down with weakness in its hind legs

When to Seek Immediate Veterinary Care

Seek immediate veterinary care if any of the following apply: your dog has eaten macadamia nuts coated in chocolate, seizures or decreased consciousness have occurred after ingestion, your dog has consumed a nut mix containing grapes or raisins, or a small-breed dog has ingested a large amount relative to its body weight. These situations constitute emergencies.

Veterinary Diagnosis Methods

Veterinarians diagnose based on a combination of the owner’s account and the pet’s clinical symptoms. Since there is no specific test kit for nut toxicity, providing accurate information is crucial. What owners should provide: - The type of nut ingested and an estimated amount - How much time has passed since ingestion - The product packaging (to check for chocolate or xylitol content) If necessary, the veterinarian will perform blood tests to assess liver and kidney function and evaluate for any metabolic abnormalities.

Treatment: Decontamination and Symptomatic Care

Treatment is broadly divided into decontamination and symptomatic care.

Decontamination: Because neurological symptoms of macadamia nut toxicity can develop rapidly, inducing vomiting at home is not recommended. A veterinarian may consider inducing vomiting or performing gastric lavage in a clinical setting only if they determine that a significant amount of the substance remains in the stomach.

Activated charcoal administration: A single dose of activated charcoal may be administered at the veterinarian’s discretion to reduce toxin absorption in the intestines.

Fluid therapy: Intravenous fluids are administered to prevent dehydration and assist in eliminating toxins.

Temperature and pain management: If fever is severe, antipyretic treatment is provided; for muscle pain, the veterinarian prescribes analgesics dosed according to the pet’s body weight.

A veterinarian examining a puppy at an animal hospital

Home Care: Managing the Recovery Period

Most cases of macadamia nut toxicity resolve on their own within 48 hours. However, careful home care is essential during the recovery period.

Hydration: Ensure your pet has access to plenty of fresh, clean water.

Dietary Management: Once vomiting has stopped, offer small amounts of easily digestible, bland food for 12 to 24 hours.

Activity Restriction: Prevent slipping on smooth floors and avoid stairs or jumping from heights until hind limb strength returns.

Monitoring: If symptoms do not improve after 48 hours, return to the veterinary clinic.

A recovering puppy resting comfortably at home, with a water bowl placed nearby.

Prevention: Rules for Storing Nuts

Nut poisoning is 100% preventable. Store nuts such as macadamia nuts, walnuts, and pecans out of your pet’s reach. Accidents often occur during holidays or home parties when pets sneak snacks left on the table. Be sure to inform family members and guests in advance that they should not feed nuts to your pet.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Is even one macadamia nut dangerous?

Even small amounts (0.7 g/kg) have been reported to cause symptoms in small-breed dogs, so caution is advised even if your dog ingests just one or two pieces. While large-breed dogs may experience mild or no symptoms after consuming a small amount, it’s always safest to call your veterinarian for advice regardless of how much was eaten.

Can cats also suffer from macadamia nut poisoning?

According to veterinary textbooks, macadamia nut toxicity has only been reported in dogs to date. However, due to the high fat content of nuts, cats may also experience vomiting or digestive issues, so if your cat has eaten nuts, you should consult a veterinarian as well.

Is it safe to induce vomiting at home?

Never induce vomiting on your own. Macadamia nut poisoning can cause neurological symptoms to develop rapidly, so inducing vomiting at home is not recommended. Home remedies such as giving salt water or hydrogen peroxide can actually pose additional risks, so this should only be done under the guidance of a veterinarian.

Is peanut butter okay?

Unsweetened peanut butter that does not contain xylitol (birch sweetener) can be given in small amounts. However, always check the ingredient list to confirm whether xylitol is present. Peanut butter containing xylitol is extremely dangerous, as it can cause hypoglycemia and liver damage.

My dog ate macadamia nut cookies—what should I do?

Macadamia nut cookies often contain chocolate, butter, and sugar, which increases the risk of toxicity. If the product includes dark chocolate, your pet may be at risk for both macadamia nut and chocolate poisoning, so please take them to a veterinarian immediately.

Primary vs. Secondary Veterinary Hospitals: A Comparison

Comparing Dog Vaccine Types (3-way, 5-way, 7-way): Differences and How to Choose

Pet Insurance Enrollment Timing Comparison: When Is the Most Advantageous Time to Enroll?

Dog Lungworm Infection: Symptoms, Transmission Routes, and Treatment & Prevention Guide

Dog Tapeworm Infection: Symptoms, Transmission Routes, and Treatment & Prevention Guide

Coccidiosis in Dogs: Symptoms, Transmission Routes, Treatment, and Prevention

Firm Lump Under a Cat’s Skin — Early Symptoms, Diagnosis, Treatment, and Prognosis Management of Soft Tissue Sarcoma

Acute Kidney Injury in Cats: Symptoms, Causes, and When to Go to the Vet You Must Not Miss

Canine Ehrlichiosis: Symptoms, Transmission Routes, and Treatment & Prevention Guide

If Your Cat Develops Kidney Cysts — Symptoms, Causes, and Management of Polycystic Kidney Disease

References

[1] Peterson ME, Talcott PA. Small Animal Toxicology, 3rd Edition. Elsevier, 2013.

[2] Schaer M. Clinical Medicine of the Dog and Cat, 4th Edition. CRC Press, 2022.

[3] Plumb DC. Plumb's Veterinary Drug Handbook, 10th Edition. Wiley-Blackwell, 2024.

[4] Hansen SR. Macadamia nut toxicosis in dogs. Veterinary Medicine, 2002;97(4):274-276.

[5] Gwaltney-Brant SM. Macadamia Nuts. In: Blackwell's Five-Minute Veterinary Consult Clinical Companion, Small Animal Toxicology, 3rd Edition. Wiley-Blackwell, 2024.