Free to good home

I adopted Cooper when he was 8 weeks old. He is a pitbull mix (we believe it may be lab or dalmatian) His litter of 8 was dropped off in a gym bag out front of a vets clinic that was shut down in NC. I have 3 other dogs in the home, one dog who is almost 10 years old (Jackson). Jackson has essentially been a Dad / older brother to Cooper since we brought him home. I got married this past year and we both had 2 dogs and integrated our family. Things have been a bit rocky as you would imagine but really thought we had gotten past that. This week however Cooper has become aggressive towards the older dog for some unknown reason. I cannot even have them in the same room together. I need to find Cooper a loving home where he is with either a female dog or by himself. He is a very sweet dog to humans, very very playful, lots of energy. He would do really well on a farm or ranch. My wife owned a 20 acre ranch when we met and Cooper loved going up there for weekends and running the 20 acres. He has a very good sense of smell. Would be a really good hunting dog or trained for law enforcement. He has been neutered and microchipped.