We adopted a dog 2 days ago. He is a 4 yo neutered lab mix. We thought he would make a great companion for our 2 yo neutered black lab. Since we have brought him home we have noticed that he is acting aggressive around the horses. When he sees them he growls and barks ferociously. It isn't a curious bark. It is definitely a mean, showing teeth bark. Yesterday I was working the horses and he could see me threw the back door. He actually chewed up the inside of the back door he was so worked up about it. Do you think there is any chance that this dog will come around? I am so worried about the horses getting hurt. I have no intentions of letting him loose with the horses and they are in a 5 ft wire mesh fence. But what if he accidently gets out. For example, I am out working the horses and someone accidently lets him out of the house. I hate to give up on him but I worry about my horses safety. Any suggestions would be greatly appreciated.