It happened to my yorkie for the first few day, it is very stressful for the new puppy to move to a new home and it may trigger tummy upset or infection. Now my little girl is 6 months old already and she is very healthy.
We have our 约瑟 since she was 10 weeks old, she is very quiet and seldom barks, she only barks when we take her toy from her mouth or when she get too excited when we play with her. When we have guests coming to our house and ring the door bell, she will try to bark but she will stop as soon as we hug her. She is soooooo... sweet.