TL;DR: Macadamia nut ingestion in dogs causes temporary neurological symptoms like hind limb weakness and vomiting; while rarely fatal, you should contact a veterinarian immediately to rule out other toxic additives like chocolate or xylitol.
What is macadamia nut toxicity and what symptoms should I look for in my dog?
Macadamia nuts are a well-known toxin for dogs, typically causing neurological and muscular symptoms within 3 to 12 hours of ingestion. Common signs include:
- Weakness in the hind legs
- Lethargy
- Vomiting
- Tremors
- Elevated body temperature (hyperthermia)
Is macadamia nut ingestion an emergency for my dog?
The urgency level for macadamia nut ingestion is Medium. While ingestion is rarely fatal and most dogs recover within 24 to 48 hours, you should take the following actions:
- Contact your veterinarian or an animal poison control hotline immediately.
- Seek professional care if the nuts were coated in chocolate or contained xylitol.
- Monitor for severe signs like an inability to stand or high fever, which require immediate attention.
How does providing a photo of the product help the veterinarian triage my dog?
Sharing a photo of the nut packaging or the specific product your dog ate is a vital tool for your veterinary team because it allows them to:
- Confirm the exact type of nut and identify other dangerous ingredients such as cocoa, raisins, or artificial sweeteners.
- Estimate the total dosage consumed relative to your dog's weight.
- Quickly determine if the treatment protocol needs to be adjusted for multiple toxins.
Clinical Context (Merck Veterinary Manual)
Ingestion of macadamia nuts by dogs is associated with a nonfatal syndrome characterized by vomiting, ataxia, weakness, hyperthermia, and depression, with dogs exhibiting signs after ingesting as little as 2.4 g/kg body weight. Clinical signs, including tremors that may be secondary to muscle weakness, typically develop within 12 hours of ingestion and generally resolve within 12–48 hours without treatment, although severe cases may persist up to 72 hours. Diagnosis is based on a history of exposure and clinical signs, with differential diagnoses including ethylene glycol toxicosis, ingestion of hypotensive agents, and infectious diseases. Treatment involves inducing emesis with apomorphine or hydrogen peroxide, or gastric lavage in sedated animals, followed by administering activated charcoal (1–4 g/kg, PO). Symptomatic treatment includes thermoregulation, correction of acid-base and electrolyte abnormalities, electrocardiographic monitoring, and urinary catheter placement.
Chapter: Toxicology
Source: The Merck Veterinary Manual, 11th Edition (Page 2967)