It's common for pet owners to impart human characteristics, also known as anthropomorphize, to their dogs, cats, and other non‑human companions. For example, when people shower their pets with love, they often imagine that they love them back; even though " love" is a cultural construct we humans invented to describe complex changes and reactions in body and brain chemistry.
"Mice, rats, horses, and rabbits are known to react to pain by grimacing in their own way."
But in some ways, humans and other animals do experience emotions and related phenomena similarly. For example: pain. Because all mammalian brains share the same basic structures and chemicals, mammals tend to experience and express pain in similar ways.
There are documented cases of dogs experiencing phantom limb pain, a neurological phenomenon where pain lingers even after a limb has been amputated.
Also like humans, there's plenty of evidence that mammals express pain through involuntary facial expressions. When a person touches a hot stove, she's likely to jerk her hand away and grimace in pain. Mice, rats, horses, and rabbits, too, are known to react to pain by grimacing, in their own way.
For example, when rabbits experience pain their whiskers stiffen, their eyes narrow, and their ears flatten: the rabbit version of a grimace.
Non‑mammals also experience pain, of course, although their lack of facial expressions makes it harder to gauge exactly how they experience and process painful stimuli.
Even though humans and other animals generally experience the world in very different ways, at least when it comes to pain, humans and non‑humans may be more alike than different.