Originally Posted by
Saravat
Her behavior has nothing to do with whether she's been spayed or is/is not in season, sheesh.
Are you absolutely certain she isn't having seizures? Did you ask your vet about that specifically?
Has she been outside by herself at all lately (where something could have happened)?
It's possible she's hearing something outside of your hearing range that is panicking her.
It might not hurt to get in touch with her breeder/the person you got her from, and ask about any similar behaviors in her parents or siblings. If none of this helps at all, then I'd advise you to get in touch with an established Border Collie breeder and describe what's going on and see what they advise. If there are reputable dog trainers in your area, then you might bring it up with them as well.
Good luck. It sounds like the poor girl is having a rough time.