My dog is suddenly afraid of neighborhood park

My dog is acting very strange. She is a 4 1/2 year old border collie, spayed female.we have lived in the same neighborhood, and frequented the neighborhood park - like twice a day. She goes nuts when we are ready to go to the park, or sing the "parque!Parque" song k. She chases the ball with joyful, workmanlike focus and doesn't socialize a whole lot. She isn't fearful of other dogs, she mostly ignores them in her focus. She is usually reluctant to leave the park, and She really likes people. at doggie daycare, she is a play monster.

Then, just the other day, we are tossing the ball for her , and she just runs towards home without me. I catch up with her (she was waiting for me a half block away) and she looks afraid and pulls me home once I get her leashed up. There had been only two other dogs in the park, and there was no altercation or loud noises. I can think of no incident in the prior days. The next morning we go again and go to the other end of the park - she appears a little uneasy, but she does not run off. In the evening, she is uneasy again but seams to relax and is fetching.... Until she takes off again towards home. There were a smattering of people and dogs there, but nothing out of the ordinary. I had explained what was happening with Mandy to my neighbors while we were there, and when she ran off, I asked them if there was something out of the ordinary. Nothin'. The next morning she won't even walk in the direction of the park. I drove her to another dog park and she was normal - not afraid, and back to chasing the ball. Today we drive by the neighborhood park and she is all tail wagging happy looking at the park and all the other dogs, so I stop at the far end, and she bounds out the door. She is "greeted" by some other dogs without incident, but After retrieving once, she runs to the car, I let her in and she lays down, cowering.

At home she is eating and sleeping as normal. She has no limp or other injury apparent to me. Other parks do not affect her. It is just going in the direction of the park seems to fill her with dread. I will not try now for a while - I am sure I am just reinforcing the fear reaction. My husband thinks that a neighbor in that area has installed some kind of ultrasonic pest repellent device. But why are the other dogs not apparently affected? And how could we locate this devise?

or could it be something else? Does BT have any ideas?

Edited by bootygirl 2013-07-29 11:35 PM