My goodness, I am so sorry to here this! How sad for both of them!
Your heart must be heavy too.
I may be anal but I won't be letting Cerise go out to potty. She is too small and too many horrors can happen. She will use the potty box. Two of them. One upstairs and one downstairs. She will only go outside somewhere when we are away from home, and ONLY by being in her harness/lead with me, with her.
I also will not have her around big dogs. Socialization is important, and she can be the smartest of all Yorkies, but it's the other dogs, and sometimes their owners, that I don't trust.