Depending on how old the puppy is it could be anything from a bone problem during the process of birth, or it has sprained it's leg by playing. As any dog owner knows puppies are like little bombs going off running here and there and tumbling and falling. Please take your pup to the vet to have that leg checked out.
Any puppy who will not eat or drink needs to see a vet. Could be anything, but she needs to be checked.
A Mom could die if she had a puppy or a placenta stuck still inside her and was not brought to the vet to have it removed. A puppy sometimes dies after birth, it is called "fading puppy" and it is thought that there is something wrong with the puppy and it is natures way of taking care of it.
I have no clue. Maybe you should take it to the vet.
None, what is wrong with puppy?
Tapeworm
It could maybe be the food that they don't like.
T-U-F-F- Puppy - 2010 Dudley Do-Wrong Puppy Unplugged 1-23 was released on: USA: 28 April 2012
your eating too much or not exercising enough
Could have eaten something weird. Maybe you changed his food? Gave him a new kind of treat?
If you are asking about age/weight for a child to ride up front in a car, you are in the wrong place.
This question should be directed at a qualified VET - not to a forum where you are unable to confirm someone's qualifications ! People could say anything on here - and you wouldn't know if their information was wrong until your puppy died !
Nothing is wrong with your dog, it is that you are allergic to the breed of dog.Or it's on fire.