
The 
American Bobtail is a relatively new and uncommon 
breed of 
cat which has appeared since the late 1960's. It is most notable for its stubby "bobbed" tail about one-third to one-half the length of a normal 
cat's tail. This is the result of a genetic mutation affecting the tail development, similar to that of a 
Manx. The 
cat is not related to the 
Japanese Bobtail despite the similar name and physical type — the breeding programs are entirely unrelated and the gene causing the mutation is entirely different.
American bobtails are a very sturdy 
breed, with both short or longhaired coats. Their coat is shaggy rather than dense or fluffy. They can have any colour of eyes and fur, with a strong emphasis on the "wild" tabby appearance in show animals.
According to legend, bobtails are the result of a crossbreeding between a domestic tabby 
cat and a 
bobcat. Yodie, a short-tailed brown tabby male, mated with a seal point 
Siamese (
cat) female to create the 
Bobtail's original bloodline. Then 
Birman, 
Himalayan (
cat) and 
Himalayan/Siamese cross elements were added to the bloodline. Most of the early bloodlines have been eliminated. Although this is genetically possible, the 
bobcat/domestic cat hybrids, particularly the male, would probably become sterile. The unusual tail is actually the result of a random spontaneous genetic mutation within the domestic 
cat population or is related to the dominant Manx gene.
This 
cat's original appearance genetics were modified in the 
breed to form a new and improved
 breed which comes in all colors, categories and divisions. New shorthair versions have appeared where once only longhair versions were fully recognized. These new lines, which invoke a gentler sweeter 
cat with the remaining wild look features, may have begun in Florida It is still permitted to outcross the 
Bobtail with domestic stock, so long as the currently small gene pool is kept healthy. 
Manx and 
Japanese Bobtails are not used in the integrated matix.
The breed was recognised by the International 
Cat Association in 1989.
Development and Conformation AppearanceDevelopment–
Bobtails require two to three years to develop, slower than many domestic 
cat breeds.
General– An ideally naturally occurring hearty short-tailed 
cat.
Body–Moderately long and substantial; semi-cobby; stocky; noticeable rectangular stance; boning substantial; chest full and broad; hips substantial, almost as wide as chest; hind legs longer than fore legs with large round feet which may have toe tufts.
Head–Broad wedge without flat planes; size proportionate to body; concave curve from nose to brow, or rise to prominent brow; broad unpinched muzzle; non-prominent whisker pads; gently sloped wide nose; full strong jaws.
Ears–Medium-sized, wide-based; equally mounted on top and side of head; with rounded tips.
Eyes–oval to large almond shape; size proportionate to head; aperture angled to base of ear; medium wide spacing, deep sockets; color varies with coat color.
Tail–End of the tail visible above the back, but not beyond the Hock, while the animal is in repose; straight, (or curved), slightly knotted or have bumps.
Coat:
- Shorthair– length medium to short; texture resilient; all-weather; double coat with undercoat.
- Longhair– length semi-long, tapering to longer on ruff, britches, belly and tail; texture shaggy, non-matting, somewhat resilient; double coat with semi-dense undercoat of seasonal variation.
HealthDisquality ones with bad hips and Rumpies (tail-less 
Bobtails with a shortened spine). These are generally not acceptable due to increased health problems.
You can see more American Bobtail cats on 
gallery.