Could've just been a fluke thing. Maybe he had a belly ache or a reaction to the benadryl mixed with the food. Could have been a reaction to the ants. Those things are wicked. As long as there was no blood, and he is acting normal today I wouldn't worry too much. Just keep an eye on him. See if he eats at his next meal and keeps it down. Also, when he is out to do his business, just check and make sure he doesn't have diarreah.
Hugs to tank this morning. :winkle:
I don't think it's anything to be too worried about... Odin threw-up like that once, and nothing ever developed from it... isolated insidence. As long as it doesn't become a pattern, I wouldn't worry too much. A lot of differant things can make a dog throw-up, most of them aren't anything to be worried about. Just monitor the situation.