Oh, I am so sorry, Rubystars! It must be hard losing a pet after only 5 years. I would imagine that ferrets are pretty smart; they must be related to dogs. I read that foxes live only 2 years, and they are also pretty smart. It's sad when smart animals live short lives.
I didn't know that about foxes!
Ferrets aren't closely related to dogs but they are in the same order as dogs, cats, bears, hyenas, etc. (Carnivora)
They are in the same family as weasels/mink/wolverine (Mustelidae)
Their closet wild relative is the European polecat (a type of weasel). It's like the wolf is to the dog or the Egyptian desert cat is to the domestic cat.