<human>: Hello,
My pup about 6 months almost 7 months now has occasionally stopped eating normally. What I mean by this is previously, when I fed him each time, he eats all of his food. I feed him twice a day morning and evening. Usually after dispensing his food into his bowl, he would devour it. Now, when he's ready to be fed, I leave his food there and he goes to it and smells it and runs away. At times he would eat it all, but this past weekend, he just takes a few bites and runs away. He eats most of it later if I stay there and tell him to eat he starts eating but now he just doesn't eat all of it. He usually has a big appetite, but now i'm not sure what's going on. Do I need to change foods? Is he sick? Should I take him to the vet? or is this completely normal?

Can you succinctly summarize the text in 1-3 sentences?
<bot>: Dog usually eats all his food in one sitting, now he doesn't eat it all. Eats parts and leaves it.