Dog Rescue – Need to Re home

Hello can anyone recommend any local rescue groups ? I took in a dog that was going to be sent to the pound in December that has now turned aggressive towards my son. Our home is normally full of kids and I don’t want to risk it . He’s a calm older pit bull / lab mix I’m assuming . But for some reason has become grumpy towards my son. I don’t want to go the pound route. So any help is appreciated . Thanks !