What Is the Bobtail Effect in Kittens?

This mutation isn’t the same as the Manx mutation -- it is completely different. Kittens born of a wild bobcat parent and a domesticated cat parent can have the mutated gene that eventually presents in that cute, rounded little stump-tail. Forgive yourself if you see a kitten with a bobtail and you jump to the mistaken impression that his tail broke off. Because it’s not something very common, your reaction is actually normal.

Siamese cats have a slight kink in their tails, making this a mild version of the bobtail effect. House cats have been seen with bobtails as far back as 1896. Brehm Martens and Jean Bungartz wrote about bobtailed cats born on the Sunda Aisles and in Japan, showing that this mutation developed well over a century ago.

Not all kittens born with a bobtail will have the same type of tail. Some will have a tail of normal length, but with a definite kink in it. Other kittens are born with a short and twisted pom-pom, giving the kitten the look of having a pom-pom stuck on his little behind. In between, all lengths and ranges exist, making these little furbabies distinct in their appearance.

If you know a bobtail kitten, pick him up and place your fingers on his little bobtail. You should feel a bony knot where his tail vertebrae have fused together. This is not a painful condition, unlike a Manx kitty. While you may be used to seeing a kitten with a long, graceful tail waving through the air as he gambols and plays, rest assured the mutation in his tail won’t cause any health problems.

Several different bobtail cat varieties have been identified, including the Thai bobtail. These kitties are usually color pointed. The Karel bobtail, or Karellian, is either a shorthair or a semi-longhaired bobtail said to be identical to the Japanese bobtail. The Kuril bobtail, also called the Curilsk, is a compact, smaller cat with a bobtail or a pom-pom tail.


Here in the U.S., the American bobtail, which has been bred from the bobtail cats found in Arizona, develops most in shorthair and semi-longhaired varieties. This furbaby usually has a sweet little powder-puff tail that is usually only about one-third of the length of a normal tail.

Here are some characteristics of one specific type of bobtailed kitten -- the Kurilean. These kittens grow to be medium-sized to larger cats, with strong, muscular bodies and solid bone structures.

A true Kurilean bobtail has a tail with a flexible base. This cat’s tail comes with several curves or kinks. You must be able to move the base of the kitty’s tail -- try not to squirm, because this doesn’t hurt the kitten. As with other bobtail kittens, the length ranges from almost one-half inch to almost four inches long.