I am kinda concerned about the nails of the new Russians that we adopted. Can anyone tell me what the average length of nails are for them? Is it normal for them to walk on their nails rather than their actual feet? Can we trim or file them or should a vet do that? They also kindof drag their shells when they walk instead of holding themselves up and using their legs more. Is this normal or could it be a hint of MBD? Thank you in advance for your help!!