My budgie do not exert much pressure on its effected foot.And two claws have no nails..it also seem to be lethargy and week.plz tell me the cause and treatment?
Nobody, not an avian vet, nobody, can tell what is wrong with your bird or the treatment over the Internet. You must get your bird to an avian vet, and if you don't have an avian vet within driving distance, then call a breeder and find out where they take their birds.