my dog shakes-APBT

Question
as a small pup 9-11 week old my dogs left leg would shake but i just figured it was because his muscles were not developed yet. Now he is 4 months old and occasionally his body  or muscles shake as if he were cold?

Answer
hi, i seen many puppies shaking ( one leg or other or both), that's normal, 4 month old shake probably__ he's cold, he's scared or excited as well( just be sure he has all vaccines and worming at this age) dogs who are raised on the back yard(outside) has a higher tolerance on weather condition, they're more tough, than this one raised and grown in the house, they're living a human life!! my dog is 12 years old and he's shaking all over, when it's cold, or if he's upset, nervous, scared... he was born and raised in the house since he was 6 weeks old, even he had a tough life, he's still a house dog, very sensitive....but there's not a joke when it comes to face it a challenge....... house dogs are just not that much tough as yard dogs, but they can be as much rough , when they need to be...in the game, heart....... sincerely