Rather than referring to the amount of danger or potential for harm when comparing BP's with some other animal, I would try to create a more positive or humorous association. As an example, BP's are often called the "pet rocks" of the snake world, because their defense is to become a ball of snake and act like a rock.
In fact, I wouldn't even put the word "danger" in my letter. So, instead of writing "Ball pythons are no more dangerous as pets than dogs or cats," you could reword it "Ball pythons are just as safe, if not safer, as pets, than dogs and cats." Same meaning but it creates a different mindset in the reader.