"We cannot sleep, we cannot eat, we cannot laugh … all we can do is cry," Sarah Scheele wrote online after Shadow's death. "Denis has trouble focusing on work … not being able to put [away] the horrific memory of Shadow running and leaping into his arms screaming in pain. ... As his mommy, I feel so lost. I can't sleep and I can't stop crying. My days are so empty without my little boy."
The Vermont Supreme Court ruled earlier this year against a plaintiff who sought damages for the emotional loss from a cat's death by veterinarian negligence.
Blythe believes that case will guide the justices in this one. "The Scheele's mission is they want to achieve a change to American tort law. They're not trying to exact revenge against Lewis," he said.
Groff, the Scheeles and other animal rights advocates are optimistic the court will move towards change.
"Pets are not property," Martin Mersereau of People for the Ethical Treatment of Animals told ABCNews.com. "In the law's eyes they are, but things are changing. Animals are family members, animals are loved -- in many cases -- like children."
The Scheeles' case, he said, is helping to facilitate change in how the courts view killings of beloved animals. Of the average 500 animal cruelty complaints filed with the group each week, he said, the majority involve pets harmed -- often shot -- while outside unsupervised.