Our family dog an almost 14 year old beagle named Bobbie. My stepfather found him at work when he was 3 years old. He was amazing and had typical beagle behavior. A couple months ago, he started limping and having seizures. Turns out, he has arthritis in his hips and was showing early signs of prostate cancer. He wasn't neutered so my mom got him neutered to save his life. Now, he's EXTREMELY aggressive. He constantly does this growling-bark thing to everyone, including the 6 people who live in the house. He has lunged at myself, my stepdad and my mom. He was NEVER like this. He did however, barked at everyone. It got to the point where if we have a family party at the house, we have to give him a tranquilizer pill but that doesn't even work. (the vet recommended it). And the vet says that the neutering has nothing to do with his aggression. What could be the other causes? His arthritis is under control with medication. And besides being old and having arthritis, he's generally healthy, the vets say he has the health of a 5 year old pup. We don't know what to do.