Lab Puppy Not Eating

Question
We got our purebred lab puppy when he was 8 weeks old, he is now 17 weeks old.  Initially he ate very well and grew quickly, however for the last 3 weeks he only eats 1 - 1 1/2 cups a day.  We use the same good quality dog food the breeder recommended and used, trying to feed him 3 times a day (he should be eating 2 1/4 - 2 1/2 cups a day.  Most of the time he now seems lethargic and does not have the happy expression a 'normal' lab puppy does.  He has a great home, goes for walks with us and during the night sleeps in a cage next to our bed.  We are not sure what to do and we are very worried for him.  Could it be his teeth?

Answer
Puppies teeth between 4-7 months.  This is still a time of fast growth for pups, so sometimes an increase of sleep is necessary to facilitate the growth.  You can also try adding some warm water to the kibble and serving the kibbles soft.  You can also get a good quality canned and mix in a table spoon with the kibbles.  Normally labs and lab puppies will not starve themselves, even if they don't eat alot.  

If water on the kibble and a little canned doesn't spark the dog's appetite, you may want to bring a stool sample in to the vets just to be safe and check for parasites.