A complete X-ray evaluation of the foot needs to be done to see if there is any bone infection
in the foot. Red streaks can indicate infection therefore it is important to get your father evaluated by a diabetic foot
specialist to know if there is any active infection. Also, have a discussion with a plastic surgeon because a reconstructive procedure is typically required to get rid of the hole in the foot. Time is of essence here so get the consultations early or the level of amputation
might subsequently increase.