Thank you again everyone for your kind thoughts and advice. I just woke up this morning and got right on the computer. I had a very sleepless night, as you can imagine, and my son (who is 12) wanted to sleep with me all night. So hubby was kicked out the bed.
I am a bit worried for my son and I hope he turns around today. He did not eat anything ALL day. I didn't want to eat myself but have some health issues that required me to stuff something in my mouth. I hope he is better today. He keeps begging me to get another dog--a bigger dog--one that Paisley can't hurt. I asked him why he wants to replace Lola so soon and he said that he didn't but he just couldn't bear not seeing her or hearing her footsteps on the floor. I explained to him that, as long as we have Paisley, we cannot EVER have another animal.
In response to some of the questions that popped up last night:
I spent some time out in the yard last night, just staring at the fence. I still cannot figure it out. The chicken wire is pulled down and it appears that Lola could have stuck her neck through one of the slats of the fence. Where her neck may have stretched through the fence, there is some blood on the fence but on the outer side of the board, and then some below on the ground (there was a gutter runoff thing that had blood on it). I would be really surprised, given her wound, that there was no blood on the inside of the fence. To me it looks as if she was trying to stick her neck through and get out. The amount of blood is very small and is not consistent at all with the wound that I saw on her neck. Her body was found approximately 20 yards from that fence, back into the middle of the yard, so she was not near the fence site at that point that she was down. There is also no trail of blood from the fence to the area she was laying in. There was no blood anywhere else on the ground, but where she was laying.
Paisley had blood right below her neck and on her chest. That area of her fur is white so it is easy to see. I assumed, at first, that it was because she was violently fighting with Lola. It wasn't until my husband came home and washed her down that we saw the big wound on her chest. In my shock, I cannot remember if there was any blood on her muzzle. I'm sure there was none on her legs or feet.
As far as the aggression issues--okay, Lola was a JRT. She could be extremely aggressive outdoors or with her toys. She loved her little toys and would grab them, growl, and shake them to death. She also loved to run out and chase squirrels. We have a few drainage pipes in the yard and every day she would run out and "check" them, bite them, and growl into them.
When her and Paisley would be let outside together after they had been indoors a lot, both of them would go running for squirrels. Lola was always nipping at Paisley's legs on the way. Paisley never acted like she cared. Lola used to try to play with Paisley in the house. Paisley isn't one of the playful dogs and she would ignore her. Finally, Lola just stopped trying and it was rare that they would play around. It was funny because just last week, Paisley actually was trying to get Lola to play. Paisley's expressions are very easily read and I could tell by her body language that she was happy and having fun. She kept swatting at Lola but Lola wouldn't play.
As for the food aggression--I guess Lola had a bit of it though I never, ever saw her even try to make a move on Paisley. Lola was the type of dog that if you gave her a treat and you looked like you might take it, she would growl at you. Paisley would not. As I said earlier, I fed them in separate rooms and I would stay down there with them. I would fill up Lola's bowl. She would wait until I filled up Paisley's bowl. When Paisley started eating, then Lola would start eating. Often times, Paisley didn't finish her food (Lola always did). Paisley would leave her feeding area and go lay on her mat that was in another area of the basement. When Lola would try to come out of her feeding room, Paisley would growl at her because Lola was "passing" by her dish. I suspect this is what happened that time I was out of town and my dad got caught up in the mess. Lola had no qualms about going for Paisley's food if she was not finished with it. So, if Paisley didn't eat, I always picked up her dish and put it out of sight.
I say Lola was submissive because if you even gave a hint of trying to discipline her, she immediately fell on her back and exposed her stomach. Even if you said "Lola, what did you do" and gave her a look. She always took a "backseat" to Paisley so to speak and constantly deffered to her on what path to take in the yard.
I really don't know what to make of that behavior. Does it sound as if they were both aggressive?
At this point, I am still about 95% sure that this was a dog-on-dog attack. I know my husband is very hopeful it was something else. I guess I won't ever know what happened in that 30 minutes. I wish so hard that I would not have cleaned yesterday and just went out to run errands. Lola would be here with me know.
And for what it's worth--Lola was about 10 lbs, had very little hair on her, and this weird thin skin, especially on the neck area. Paisley is close to 50 lbs, is VERY strong and it wouldn't have taken much to inflict this type of wound on Lola. To me, her wound was a clear puncture. The top and bottom punctures were aligned in such a way that I think the top and bottom canine teeth did it. I think she took one bite on the neck that easily went through the skin and that was it.
I'm still wrestling with what to do. The vet tech had told me about one family who had a dog they wanted to put down, I believe for excessive barking. I believe that she said my vet referred them out to some program and it worked and they were able to keep the dog.
I'm not sure if my vet will look a Lola's body tomorrow or not. She is up there at his office, in the freezer

. We have the option to go get her and bury her in the yard or do the cremation. I am a bit concerned about putting her in the yard as I don't know what Paisley will do and I don't think my husband is up for doing the burial, but who knows.
I just wish I could stop feeling so awful. I cried yesterday for at least 8 hours, was crying in bed. I had to pull myself together for my son and stop crying in front of him because I think it's making him worse. But already this morning, I can feel the tears again and I'm just feeling physically ill. I know I can't make it stop but I feel so horrible. And I know that I will forever blame myself.