first let me explain that the word is not CREATINE, it is CREATININE...i am a dietitian and work with hemodialysis patients. i would recommend that you and your father go see a dietitian. is your father on hemodialysis or peritoneal dialysis? do you know what his creatinine and blood urea nitrogen levels are?
a diet low in protein is the correct dietary step to make. his actual grams of protein/Kg of body weight intake depends on his bloodwork/dialysis situation i.ll save you the scientific explanation. there are other foods that have protein in them besides meat and fish (dairy products, legumes, etc).
get professional advice from an RD. to find an RD in your area, go to the american dietetic association website: www.eatright.org and look for one.
monitor his bloodwork.