Welcome! My name isXXXXX am a UC Davis graduate, and currently, a Medical Director of a veterinary hospital.
I am sorry to hear about this concern for Missy.
Well, only 1 nut, even for a small pom over 8 hours ago would not really be of any concern.
What about 2 more nuts?Macadamia Nut Toxicity
The above link is a very nice summary about the toxicity including toxic
Now, you'll read that toxicity was seen at doses as low as 2.7grams per kilogram body weight.
Let's say your pet weighs 8 pounds. That's about 3.6 kilograms.
So, 2.7 x 3.6 = a toxic dose as low as ~10 grams of nuts.
A single nut weighs about 2.7 grams. So, that would be about 5.5 grams ingested, but the lowest possible toxicity was seen at about 10grams.
Even if your dog weighed less, at about 6-7 pounds, I am not concerned about having ingested two more nuts.
I would still read the link I provided very carefully so you know more about toxicity and symptoms, but I think you are in good shape, and no preventative measure needed at this time.
Please let me know if there is anything I did not cover for you. I hope that information has been helpful.
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