Yes, we all get the great logic of, "Why is one animal more important than any other animal? or "Why is it okay to kill a cow and not a dog?" Yes, thank you for your mind blowing logic. I think we all understand by now the hypocrisy of it all. I think this argument was used in a junior high school debate.
From an ethical standpoint, there probably is no difference. Both animals are breathing and alive and feel pain. However, human beings are hypocrites. We do prefer certain species over other species. We do like cuddly, furry ones over other species like snakes or reptiles. It's the way it. Given the strong emotional connection between humans and dogs/cats, the government felt it was necessary to protect such animals. It is hypocritical? Yes, but we live in a hypocritical world. If you don't like it, change it.