Sometimes elderly people don't realize that they are getting too old to do the things they have always done ... like drive a car, walk to the mailbox, or house train a puppy. Or, sometimes they might realize it on some level, but not want to admit it to themselves or to anyone else. Getting old is so hard, both physically and emotionally.

Perhaps Grandma either forgot how difficult a puppy can be, or didn't realize that she is now too old to handle it.

While it is indeed a bad situation for the puppy, I also feel for the people involved.

Perhaps you could help them find an older, trained calm dog at a local shelter? Or even on Petfinder, if it is fairly close, and volunteer to pick it up for them?

I hope it works out for everyone involved.