Although the blue whale holds the record for the largest heart of any creature on the planet, its heart consists of a mere 0.12 percent of its entire body mass. Most animals — including humans — have a heart-to-body ratio 0.6 percent. The undisputed champion in this category should not be surprising. Man’s best friend, the dog, has the largest heart-to-body ratio in the animal kingdom. The canine’s overflowing, love-giving heart makes up 0.8 percent of its body.

It should also come as no surprise that the heart-to-body mass ratio for the household cat comes in at 0.35 percent.

Read more fun facts about dogs.

Read more fun facts about cats.

Read more fun facts about hearts.