I got my little Loki in March. He came from Dead Dog Beach in Puerto Rico and I know he had a tough time. He's about 2.5 - 3 years old. When I got him he was very sweet - a little shy and standoffish. He hated being alone, so I had them send me another little dog from PR that he used to love and pal around with. She's a 6 yo female. They get along fine, but Loki is kind of competitive with her as far as my attention goes. Anyway, when I take them for walks, Loki has been getting more and more aggressive with people, other animals, etc. He freaks out when he sees another dog or a deer. He really goes nuts and stays nuts for 15-20 minutes afterwards, pulling on the leash and just kind of frantic. Now, he barks and lunges at people on the other side of the road, kids on bicycles, etc. He tried to nip my neighbor who he was always friendly with before. What is happening to my sweet little dog??? He is very high-strung. I'm wondering if maybe he needs Prozac or something?