Answer:
2 weeks up to 3 but it matters what type people should go to a vet to check if it is a problem
The proper term is called "shedding". A bird moults, a dog sheds. Dogs normally shed during weather changes. You should brush them out very day. If you see a lot of fur being shed and bare skin or sore spots or itching excessively, then take your pet to your Veterinarian to be checked out.