15 to 20 minutes probably twice a day. Stop with the chicken meat. That is just as bad and if he hadn't digested it fully and you kept feeding him he could be come impacted which can lead to a prolapse. This is probably what happened. When feeding mice or bird tissues the only other item that you should feed during its digestion is worms. Earth worms or night crawlers because they act as a stool softener and are easier to digest. Its not your fault. You didn't know. Just do your best to care for him while you setup an appointment with a vet. I cannot stre3ss enough how important it is that he gets vet treatment fast. If you wait too lang it could be too late.