A 4 year old boy was attacked by his moms dog, the parents are not together, what are the dads rights ?

the boy was attacked in his moms home by her dog , she is the custodial parent and the dad wants to get custody of him. the child tells the mom he doesnt like her , he wants to live with his daddy, cps refuses to help . what are his right in protecting his son? the mom still has 3 dogs in the home with 3 children and there is no law requiring the attack dog to be put down......it has been quarentined for 10 days.