Although these longer tail types are of purebred Manx ancestry, they do not possess the dominant gene so cannot pass it on.
However, since the Manx tail mutation gene is dominant, these longer-tailed purebred Manx cats may still be used in breeding programs and may even be considered in an effort to help avoid the fatal spinal deformities that sometimes result in tailless Manx cats.
Regardless of the genetic and historical reality, there are various fanciful Lamarckian folktales that seek to explain why the Manx has a truncated tail.
Whether the shorter tailed kittens of these varieties are labeled Manx is up to the breed standard consulted.
Manx cats' tails are classified according to proportional tail length as kittens (the proportion does not change after birth): Kittens with complete tails may be born in a purebred Manx litter, having not inherited the taillessness appearance at all.
Depending on the country and cat organization referenced, rumpy, rumpy risers and stumpies are the only Manx cat tail types that fit the breed standard for Manx cats.
The longer cat tail lengths seen in some Manx cats are considered a breed fault, although they occur as naturally in the breed, but not as often, as the shorter tails.
Manx cats have been exhibited in cat shows, as a named, distinct breed (and with the modern spelling "Manx"), since the late 1800s.
In that era, few shows provided a Manx division, and exhibited specimens were usually entered under the "Any Other Variety" class, where they often could not compete well unless "exceptionally good in size and markings".Early pet breeding and showing expert Charles Henry Lane, himself the owner of a prize-winning rare white rumpy Manx named Lord Luke, published the first known (albeit informal) breed standard for the Manx in his 1903 Rabbits, Cats and Cavies, but noted that already by the time of his writing "if the judge understood the variety" a Manx would be clearly distinguishable from some other tailless cat being exhibited, "as the make of the animal, its movements and its general character are all distinctive." Not all cat experts of the day were favourable toward the breed; in The Cat: Its Points and Management in Health and Disease, Frank Townend Barton wrote in 1908: "There is nothing whatever to recommend the breed, whilst the loss of the tail in no way enhances its beauty." The Manx was one of the first breeds recognised by the Cat Fanciers' Association (CFA) (the predominant United States-based pedigreed cat registry, founded in 1908), which has records on the breed in North America going back to the 1920s.As with the sometimes-tail-suppressed Schipperke dog and Old English Sheepdog, tail suppression does not "breed true" in Manx cats.The Pixie-bob breed also has a short tail which may or may not be genetically related or identical to that of the Manx.More will be clear about tail genetics as more genetic studies are done on cat populations and as DNA testing improves; most domestic animal genetic work has been done with dogs and livestock breeds.Attempting to force the tailless trait to breed true by continually breeding tailless Manx cats to tailless Manx cats has led to increased negative, even fatal genetic disorders (see below).