I understand how she felt. I had a little Miniature Daschund for 17 years, a female named Fritzy, and Fritzy always kept me company until wee hours in the morning while writing GNGS. She rarely left my side. When I'd turn off the computer and the closing music played, she'd jump up and wag her tail.
It's almost 3 years now, since she's been gone. She died the day GNGS hit the Barnes and Noble bookshelves. When I knew she was close to her time, I wanted her to be comfortable and die at home, but if I saw any pain, then I would take her in to be put to sleep immediately. I witnessed no pain until the morning of Aug 29th. She yelped out, seemingly at invisible things (angels?) coming to get her. I didn't know if she was just scared or if it was a pain yelp, but I woke Bob up and said, "We're taking her right now."
I held her on the way to the vet as Bob drove. She seemed pleased I didn't leave her home alone on this journey that she had no clue of its purpose, because she began wagging her tail as if to say, "thanks for not leaving me." Then she died in my arms. Bob and I pulled over and cried our eyes out. I buried her near where she always used to lay in a spot of sun. I still miss her so much.
Anyone who has ever loved a pet understands, but pets become as equally attached to us as we do to them. I remember asking Dennis a long time ago how Natalie's pets reacted to her absence. He said they had probably gotten used to her absence while she'd been away filming Brainstorm, but that Natalie's daughters had found such comfort in the pets while they grieved. He said one of Natalie's dogs always kept looking up the stairs toward her bedroom.