The sooner your cat receives treatment, the better chance he'll have to regrow his hair.
Because the stem cells that continually supply the follicles with new cells do not appear to be affected, the follicle retains the potential to regrow hair.
Coriander (cilantro ), garden cress, and dill are short-lived annuals that, when cut for harvest, do not regrow.
Fragments shorter than 2.5 cm do not always regrow but segments 5-6 cm in length or longer regenerate readily.
The good news is that most cats will regrow their fur once they receive appropriate care for their situation.