I know he only ate one, but now I am concerned because I guess it takes a couple of days for a problem to arise, and tonight he has had horrible diarrhea. It could be anything, but it also could be the acorn toxicity. Not sure what do on the night before a holiday. I guess I will just watch him and see what happens. Man, if it is not one thing with this puppy, it is another. Geesh!
Did your dog eat a lot of it? Because if he did, you might want to monitor his behavior for the next 12 hours or so. Better if you just bring him to the vet.