I've been following this thread as I am a native Pennsylvanian, recently relocated to the south, as well as a horse person. I worked professionally in the horse industry in Pennsylvania since 1999 until last year, and may have met Susan somewhere in my travels during that time. Horse women are an independent, unique bunch, who have no problem holding their own in this world.
Hippy hippy, you asked about a herding dog and whether or not it would kill a small animal. I have owned one full blooded collie and right now have a German Shepard/ collie cross. Certainly not a professional when it comes to dogs, but I can tell you my experiences.
My full blood collie was the sweetest animal that could be. He would pin our small dog down very gently and lick her face to wash it with the utmost care. It was precious to watch!
BUT, he was a very infamous chicken thief and killer. We got him from his breeder when he was 6 months old and he had been raised around chickens and kept in the chicken coop at times, so they were something he was very familiar with. He would sneak off to our neighbors and snatch a chicken, bring it home, kill it and eat it. I found it hard to believe until I actually caught him in the act.
Around the same time, we had a neighbor who was poaching deer and dumping the carcasses on a part of his brother-in-laws land that adjoined ours. We found out about the poaching when our dogs started dragging home deer parts. We had so many various parts at one point, I could have built many deer myself!
Our current German Shepard/ collie cross is also a very sweet soul. While I cannot imagine him purposely hurting anything, he does love to herd and has taken off to chase deer that roam our hay fields. He is extremely protective of me- my husband and I will sometimes play wrestle, and Pudge will insert himself in between us to break things up. He has never been aggressive towards my husband, but my husband takes his interest as a sign that no one is going to "hurt" his mommy!
We also inherited a Great Pyrenees Livestock Guardian Dog when we purchased this farm. She is turned out with our herd of horses and she thinks it is her job to protect them. I have never her seen her do anything remotely aggressive towards the horses, and most if the time she lies close to where they are grazing and observes, but when the coyotes start howling, she springs into action. She barks, paces, turns circles and lets the coyotes know they are not welcome near her herd. I know she is not aggressive with small animals- we have a couple feral cats that frequent our barn and pastures that she never bothers, but I think if you threatened her "herd", she would be much more aggressive.
Could your dog have gotten into it with a small animal and killed it? I believe that is the most likely scenario. Many times they will give chase and if they do manage to catch the animal, they may hurt or kill it just because they do not know what else to do with it.
Hippy hippy, you are doing all you can in this situation and have gone above and beyond. It sounds to me like the police, for one reason or another, do not believe Susan would have been in that area. It also sounds like there is very dense underbrush, that would be very difficult to search, especially this time of year when vegetation is at its' peak.
Have cadaver dogs been brought in? Have the authorities searched via ATV/RTV or horseback?
