My mother owns an almost 3-year-old Chihuahua/Jack Russell mix with separation anxiety. In the beginning, he would whine, howl and urinate everywhere if left on his own but he grew out of it. Recently, he has been showing signs of separation anxiety again but it is much worse than before. Now, he begins barking and snarling when he realises someone is going to leave the room and jumps up trying to bite the person's arm or leg, even if they are just going into another room in the house and sometimes even if they leave the door open for him to follow. When we go out in the car, two of us sit in the back with the dogs (she also owns a pure Chihuahua) and he will whine, bark or both through the whole trip. When we come to the places where he knows we will need to get out, he will begin barking as loud as he can and jump at us when we attempt to open the car doors, even though the driver always waits in the car with the dogs. He is generally a very loving, affectionate dog, although I will admit that he can be a little aggressive on occasion. My mother has recently said that if it continues, she will be getting rid of him. I don't want to see him go or for him to end up in a shelter but I'm worried that his behaviour won't stop and she will go through with it. She has tried plug-ins and calming tablets, and is planning on having him neutered to see if that will calm his aggression but I just want to see if anyone else has any ideas for what can be done to stop this behaviour and save him from getting sent away.