Read over the health gaurantee you got from your breeder and make sure something like that is covered in it. Call your vet and make an appointment for tomorrow to see what is up. Sounds like worms to me. If it is in fact worms (or something else), contact your breeder after the vet's visit and let her know what's up. If it's something that is gauranteed in the health gaurantee, she should reimburse you for the vet cost. Hope everything works out and your little one is OK!