Ginger, a 3-year-old, Lhasa Apso, arrived about midnight. Her worried owners were at a loss to explain what had happened. They were awakened when she suddenly stumbled across their bed, fell to the floor and began staggering around the room. They thought she was having a seizure because she was walking “like she was drunk” and falling over.

During the examination, Ginger appeared dazed. Her eyes were glossy, and she had a stare that was at once anxious and distant. The muscles on the side of her chest were twitching rapidly, and she had a temperature of 105. The high end of a normal temperature in a dog is about 102.

The vet immediately suspected a toxic exposure or ingestion. Symptoms like these can be caused by a variety of toxins. The key to determining the correct treatment, and the prognosis is figuring out which one it was, when it was consumed and how much.

As the technicians gathered vital statistics and began initial laboratory tests, the clinician worked backwards with the owners to figure out the possible cause. Given the signs exhibited, the list of prime suspects are stimulants. Chocolate toxicity is high on the list, especially around the holidays, when it becomes ubiquitous. The active compound in chocolate, methylxanthine, acts very much like caffeine, which is also a possible culprit here. These toxins can be fatal, but rarely are. They generally respond to supportive care, such as IV fluids, induced vomiting or activated charcoal.

The doctor’s suspicion seems to be panning out; it seems Ginger did eat some chocolates earlier in the evening. However, after some back and forth trying to recall specifics, and a phone call to the house to count remaining pieces, it appeared that she had only consumed about 5 or 6 pieces, and it was milk chocolate — far below a toxic dose. But, the next piece of information ended the mystery. It was indeed the chocolate pieces that had caused the problem, but the chocolate itself did not: it was the macadamia nuts buried inside that were the offending toxin.

Yes, you can add macadamia nuts to the list of foods we cannot share with our pets, along with onions, grapes, raisins, sugarless gum and chocolate, to name a few. The most common symptoms are the ones that Ginger displayed. Vomiting, diarrhea and lethargy also might be seen, as well as the loss of the ability to use the hind legs. 

In this case, the dose was about right. Toxic reactions can be seen with doses as low as 2.4 grams of macadamia per kilogram of dog. By the way, a macadamia nut weighs about 2.4 grams, so about five is all that a 4.5-kilogram dog (10 pounds) like Ginger would need to show signs of toxicity.

The good news is that these symptoms will generally resolve with time, and no fatalities have been reported. If symptoms are mild, no treatment may be necessary. Supportive care for more severe cases might be required to alleviate discomfort, vomiting and diarrhea, as well as sedatives to relax them.

While death is unlikely, these guys can feel horrible, even with relatively low amounts of toxicity. It’s important to be aware of this toxin because its symptoms cam mimic those of other compounds, which are much more dangerous. One example is metaldehyde, which is found in snail and slug baits. Metaldehyde often causes symptoms very similar to Ginger’s but can rapidly progress and is often fatal. This situation requires a much more aggressive medical management approach, and has a far worse prognosis. If you can figure out early that macadamia nuts are involved, it may alleviate a lot of stress and prevent an unnecessarily aggressive medical treatment.

The sudden loss of function in the hind legs of a dog is typically associated with a ruptured disc, a tumor or a stroke. This condition calls for advanced diagnostic imaging such as an MRI or CT scan. These diagnostics are expensive and require general anesthesia. If the vet learns that macadamias ingested in sufficient quantity caused these symptoms, unnecessary and costly treatment can be avoided.

Until recently, macadamia nuts were uncommon in most homes. They are now a popular healthy snack by themselves, covered in chocolate, baked into cookies, added to trail mixes, etc. These treats are also very appealing to man’s best friend, and precautions should be taken to keep them apart. While dogs certainly share our taste for many foods, it is important to know which ones they should not eat.

Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to


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