I am so sorry for your loss. It does sound like it was a freak accident.
I have a big dog and a Yorkie. My husband's dog is very calm and doesn't bother my Yorkie at all.
That being said, I do play with the dogs separately. I also do not leave the dogs loose while I am gone. The big dog has earned his right to be loose in the house when I go away so if I don't take the Yorkie with me (he goes most places with me) then he is crated. At night the Yorkie is in my bed and the big dog is crated.
I do take the dogs in our yard to potty at the same time, but it is our yard and they are on leashes.
I can not imagine how hard it must be to deal with an accident like that. Neither of my dogs runs around much so not to big of a risk, although something could happen. It is unlikely to happen because the Yorkie is 9 and very calm and the 5 year old Setter is very calm as well.
__________________  It's raining Yorkies here! LOL Teek  ,Rowan  , Raksha (Grand Puppy)  , Raelyn |