Not that many dog owners are stuffing their dogs with these pricey nuts, but if you think of giving your dog anything with macadamia in it, don't. Macadamia nuts are highly toxic to dogs, and can cause immediate and potentially serious side effects within just moments of consumption.
Dogs who have been given macadamia nuts often experience a paralysis of sorts in their hind legs, walking around as if they are drunk, drugged, or sluggish. Vomiting and lethargy can also be part of the effects, as well as an increased thirst and lack of appetite. While these side effects often subside within a few hours, if you give your dog macadamia nuts, even a single nut, you should call your vet immediately to make sure that kidney or liver damage isn't detected. This is especially important if you have a younger or very old dog, or if you have a dog currently on any kind of medication.
So, stick to peanuts if you are going to treat your dog. While macadamia nuts may be a treat for you, they can be murderous on your dog, and even a single dose can mean trouble. As a side note, avocado and raisins (including grapes) are also on the list of no-nos for your dog. So avoid these foods at all costs to ensure a happy and healthy pooch for years to come.