[Blueflag]

Any animal smaller than a red fox is a potential meal to a red fox. If your terrier was in heat, then that could drive the odd behaviour.

Is there any chance the 'fox' you saw was a neighbor's Sheltie? Our Shelties have been mistaken for foxes.

[Movemout]

She is not in heat.

[Movemout]

Is there any chance the 'fox' you saw was a neighbor's Sheltie?

I know all my neighbors. We all have ten acres and none own a Sheltie.