My 5 month old puppy threw up today after a walk around the neighborhood(which we do regularly). He ate at around 3pm and the walk was at 8pm. But he seemed totally fine, still running around. But later tonight he threw up white liquid/foam a min after barking at his reflection in the mirror (which I don't know if has anything to do w/the throwing up). We've been feeding him the same food (purina beneful) and same treats. One thing I did notice though was that he has been pooping less recently. Again, I don't know if that has anything to do w/that either.. could be just him getting older. I did some research online and some said its normal for puppies to throw up as they do so easily... but some are saying it could be virus. I'm kind of worried! But I don't want to take him to the vet if it's actually not that big of a deal. Sorry for such a long description. But any advice would be really really appreciated!!