* All mammals are related: Cats, dogs, humans, and even whales all share a common ancestor millions of years ago. So, in a very broad sense, no animal is completely unrelated to a cat.
* Felidae family: Cats belong to the Felidae family, which includes lions, tigers, cheetahs, leopards, jaguars, and many others. These are the animals most closely related to domestic cats.
* Non-Felidae mammals: Animals like dogs, horses, cows, and dolphins are mammals but are not in the Felidae family. They are not as closely related to cats as lions or tigers.
Therefore, the answer really depends on how you define "related". If you're looking for an animal that is not in the Felidae family, you could say a dog, horse, cow, dolphin, etc. are not directly related to cats. But remember, all mammals share a common ancestor!