Genes Fd, fd
(= Folded ears)
Gene Fd causes the ears to fold forward and sideward.
Fd is dominant over fd. Therefore gene Fd must be present only once (Fdfd)
that its effect on the ears is visible.
Gene Fd is incompletely dominant. Folding of ears may be expressed
individually differently. Some cats have loosely forward folded ears, some
cats have tight folded ears close to the head like a cap.
(= no Folded ears)
Gene fd is recessive, that means, gene fd must be present
twice (fdfd) that the ears are straight.
Possible gene combinations
||homozygote for Folded ears
A cat must
have at least Fd- to have folded ears.
||heterozygote for Folded ears
||homozygote, no Folded
||The cat has no folded ears.
|The best known breed is the
Breeding program of Scottish Fold
The homozygote Scottish Fold may be affected by
the so called "crippling effect" (Osteochondrodysplasia), which
results in a shorter, thickened and less flexible tail and in swollen legs and
problems in the joints.
There are many discussion about the Scottish Fold, unfortunately very emotional
and quite subjective and lacking objectivity, especially when discussed by
animal protection organizations. All reports and literature refer to studies,
which are already more than 30 years old. A systematic study about this breeds
does not exist, unfortunately.
It is rather interesting that already in
Genetics for Cat breeders and
Veterinarians, 4th edition, 1999 it is something written, which critics
like to ignore and overlook simply:
Page 192: "Folded ears [cosmetic]
The homozygote FdFd has the folded ear, but it also may be afflicted with
crippling epiphyseal dysplasia which results in a short, thickened tail, swollen
feet and a marked decrease in activity. This condition was once prevalent in
Scottish Fold cats but now appears to have been significantly reduced in
incidence by selective breeding."
It is interesting that the anomaly (chapter Specific Anomalies, page
186ff) is classified as cosmetic and what one can read here in the last
As all Scottish Fold of today are mostly
heterozygote, because American Shorthair or British Shorthair are used for
breeding and mating Scottish Fold x Scottish Fold is not done, these problems do
appear very seldom.
Unfortunately the Scottish Fold Straight, Scottish Fold with straight ears,
which is the result of mating with British Shorthair, is not recognized in all
organizations like the Scottish Fold that it may receive the same titles.
I had developed breeding rules for the Scottish
Fold with the Estonian FIFe-member, which have been removed by FIFe from its web
site. That shows evidently, how much some organizations care about breeding
No mating Scottish Fold x Scottish Fold
Only mating Scottish Fold x American
Shorthair or Scottish Fold x British Shorthair or Longhair
All cats used for breeding must have a health
certificate with an X-ray.
Scottish Fold with straight ears are registered
Scottish Fold Straight, they are neither registered as American Shorthair nor as
They are also not used for breeding American Shorthairs nor for breeding British
Recommendation: No mating Scottish Fold Straight
x Scottish Fold.
Therefore one has to wait, which results the
research about the Scottish Fold in the
Feline Genome Project of Dr. Lyons will show.