periodic up-chucking of my dog...

Question
I have an approx. 9 months old Terrier mix.  he is no more than 10 lbs and pretty healthy and very active (runs around the house all the time and we also take him walks).  however, once in a while, he throws up i'd say a couple ounces of brown thick goo.  it's almost the same color as his food.  we feed him Purina ONE dry kibbles and no can foods what-so-ever to keep his bowel consistent.  not sure if it's because he is eating too much or having an upset stomach?  he is still fairly hyper and wants to play after throwing up.  right now, we feed him twice a day with about half-a-palm worth of kibbles in his dish each sitting.  sometimes he doesn't finish it all though.  is that a sign that he doesn't need that much food?  we don't give him treats much aside from rawhide chew bone for him to gnaw at when he is bored and sitting.  i hope i've given you enough information to go about this.  thank you very much.

Answer
If he is throwing up food, it may be regurgitation rather than true vomiting from being sick. Dry dog food swells in the stomach, so if you feed him too much, it just swells up and he regurgitates it.

Try reducing the amount of food or pre-moisten the food so that it has already swelled up before the puppy eats it.