whimpering chihuahua

my roommates chihuahua who is around 11 months old has been whimpering all day long, she wont sit still for long periods of time. She is around 11 months old. My roommate changes her food a lot which as far as i know isnt good, my roommate also claims to have seen her swallow a nickel about a week ago. She hasnt ate much the past couple days but is pooping

Brankica:
Hello,
with all this info I am thinking of several things. But in general, the dog should definitely go to the vet.

If the food is not good, that can cause a lot of problems for the dog, especially that it is still young and developing.

If it swallowed a coin, being such a small dog breed, it could have serious bowel problems. Especially that you are not saying it was pooped out, so it is probably stuck in the bowels and hurting the little dog.

Since there are so many changes in the behavior, I definitely can not give you a better advice than taking the pup to the vet.