Judge Deborah Griffith also ordered that the pit bull be de-fanged and micro-chipped and that he will not be adopted or fostered out. Mickey has already been neutered since mauling Kevin Vicente in February as the boy tried to take the dog's bone.
Griffith rejected a request from attorneys representing the dog to donate the $2,500 it will cost to de-fang the dog to Kevin and his family to help with medical expenses.
Arpaio agreed to keep Mickey for the rest of the dog's life and to appear annually for a status conference on Mickey. Mickey will be kept behind bars and isolated from the general public and other animals in the MASH shelter.
He also agreed that no taxpayer money would be used to train inmates on how to handle the dog.
Arpaio said many of the inmates are trained in how to handle "vicious" dogs and that there is about $200,000 in donations to help maintain the MASH shelter.
Arpaio formed the MASH shelter in 2000 after an animal cruelty case in which he termed the animals the "true victims." He renovated a section of the First Avenue Jail that is now air conditioned and can comfortably house the animals.
The case got international attention after a heated debate on social media about the cause for the attack and the fate of the pit bull.
A judge said the dog was vicious, but ruled against euthanization.
Mickey had been staying at the Maricopa County Animal Care and Control Shelter. Griffith said the MCACC will not be held for any future incidents.
"That dog is going to do a life sentence in the jail, but a nice life sentence with good food, air conditioning, his own room," Arpaio said. "I mean what else, but being loved by the inmates and detention officers?"
Mickey mauled Kevin while at his babysitter's home in February when the boy tried to take away the dog's bone. Kevin has gone through extensive surgeries, had a broken jaw and lost an eye.
Griffith made the decision in late March that while Mickey would not be euthanized, he must be neutered, defanged, microchipped and never adopted out.
Arpaio then announced via his Twitter, "My jail for animals may get a new lifetime resident, Mickey the pit bull. Inmates will care for him and not a taxpayer cent will be used."