The Manx cat’s lack of tail is the result of a genetic mutation possibly caused by inbreeding among the small population of British Shorthairs on the Isle of Man. The true or ‘rumpy’ Manx has only a small hollow where the tail would have been, although cats with residual tails are born. These are called ‘stumpies’, ‘stubbies’, or ‘longies’ depending on the length of the tail. It has a characteristic rabbit hop gait. The short coat is easy to care for.
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Health and welfare of cats with shortened tails
There is always a strong worry that the lack of or shortened tail is caused by an inherited deformity of the end of the spine. There are various different breeds with short tails (stumpy tails), which may be caused by different genetic mutations. The Manx cat’s lack of tail is the result of a genetic mutation that causes severe disease. The true (or ‘rumpy’) Manx has only a small hollow where the tail would have been, although cats with residual (stumpy) tails are also born. The defective gene responsible for the loss of the tail also affects other parts of the spine and may cause severe spinal and/or neurological problems. When two completely tailless Manx cats are mated, the defects may be so severe that many of the offspring may be born dead or die shortly after birth.
The same problems occur in at least some other breeds with short tails, although often there is not a great deal of information on these other breeds. However, with a potential risk of more severe problems, and the lack of a normal tail raises serious questions as to whether breeds should exist which rely on such deformities. Even without further problems, it should be questioned whether deliberately breeding cats without a normal tail is justified and could ever be in the cat’s interest.
Because of the problems associated with the condition required to produce a cat without a tail, this breed should not be continued.
We have limited the information about inherited disorders to those conditions that are known and proven to exist within a breed. For many breeders and many conditions, insufficient information may be available at this time to know whether any particular breed is necessarily free of any particular condition.
In general, pedigree breeds use a much smaller gene pool for breeding than domestic cats and therefore have a higher risk of developing inherited disorders. In addition, a number of ‘newer’ pedigree breeds are derived from matings between one or more ‘older’ breeds, and in these situations perpetuation of inherited problems that were seen in older breeds is likely within the newer breeds.