Sleepy chihuahua

Question
I just got an 8 week old chihuahua a couple days ago.  Is is rather little, he is
only 4 in. tall and weighs 10-13 oz.  He is not very active and he sleeps
constantly.  Is this normal for for an 8 week old chihuahua?  I though puppies
were supposed to have a lot of energy and be very playful.  He has also not
barked in the few days we've had him, he only wines/cries when he does
make a noise.  I know this is normal for the first 2 days you get a puppy
because I also have a minpin and he was shy and quiet for the first 2 days but
after that he was very playful and loud.

Answer
You should already have made an appointment with a veterinarian since most puppy purchases are covered in most states by "lemon laws" which require immediate veterinary examination.  You need to see a veterinarian ASAP.

Your puppy is a prime candidate for hypoglycemia.  His body weight needs to be carefully monitored and his fluid and food intake need to be supervised carefully.  Hypoglycemia will kill a puppy very quickly but can be avoided by good ownership.  Your puppy requires evaluation not only because his behavior is highly abnormal but because he appears to be suffering from some sort of physical discomfort (because of his whining.)  Be very cautious when vaccinating this puppy.  Stay away from ANY veterinarian who wants to give this puppy all his shots AT ONCE.  Parvo and Distemper are the most important puppy vaccinations but must be given to a small breed dog such as this one at a time with at least two weeks in between.  Do not take this puppy outside for any reason and you should avoid places where other dogs congregate because of the threat of bringing the Parvo virus into your home on your shoes.  If you must be around other dogs, put a container with bleach at your front door and thoroughly clean the bottoms of your shoes before bringing them into the house.