I am so sorry to hear about Slinky. What an awful thing to happen to her.
I know that I used to be terrified whenever one of our furkids went walkabout, which happened frequently when our children lived at home.
The ferrets were so used to our dog that I was really worried that they'd be friendly with a strange dog they'd come across and get attacked. Thank God that never happened but I can empathise with how you must be feeling.