Roxy, Come Home!

Roxy disappeared on Sunday of Memorial weekend 2012, between 7pm and 10pm. I'm heart-broken. And stumped.
  • Did she go off somewhere private to die? She was in excellent health, and, even if true, someone surely would have found evidence by now.
  • Did a coyote get her? At 90lbs, she'd win that match. And her inseperable partner in crime, Sophie, was home waiting and showed no signs of an attack.
  • Was she hit by a car? A fenced yard, private neighborhood, and with very little traffic. And County roadside cleanup is not operating at that time, certainly not responsive enough to remove all traces within 3hrs.
  • Did Animal Control get her? On Sun (of a 3-day weekend, no less), the shelters are not operating. And if she were to wind up there, she is microchipped.
  • Was she picked up by someone in an adjacent neighborhood? Unlike Sophie, Roxy is not one to roam, so I am skeptical. Still, I have distributed over 200 flyers and sent 1000 postcards in the areas surrounding my house. Not a hint of a response (other than well-wishes).
  • Was she abducted? Wary of strangers, I wouldn't expect her to easily go with anyone. But no other neighbors were home at the time to see anything unusual, so I suppose it is possible.

What could have happened? I am desperate for any clues...