Is my Scottish Fold pregnant?

l'm interested too. l admit l don't understand how a Fold x Fold mating always  results in fold-eared kittens, but it does. lf what l learned in school was correct, then it should result in 75% fold and 25% non-fold, but every Fold x Fold mating gives 100% Fold kittens (with said deformities).

This is what l thought should happen:

F  d          F  d

FF   Fd   Fd   dd

but apparently not, for whatever reason (the part l don't understand). And yes, every Fold x Fold kitten will have the condition, according to the most recent studies.

Andrya said:

 
l'm interested too. l admit l don't understand how a Fold x Fold mating always  results in fold-eared kittens, but it does. lf what l learned in school was correct, then it should result in 75% fold and 25% non-fold, but every Fold x Fold mating gives 100% Fold kittens (with said deformities).

This is what l thought should happen:

F  d          F  d

FF   Fd   Fd   dd

but apparently not, for whatever reason (the part l don't understand). And yes, every Fold x Fold kitten will have the condition, according to the most recent studies.

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This is what I found, which seems to explain it better (note, you have not contemplated fd)...

Genetics

Osteochondrodysplasia in Scottish folds is an autosomal dominant condition, which is now believed to have incomplete dominance (Takanosu et al 2008). All homozygous Scottish fold cats have two mutant genes (Fd/Fd) and have severe disease. All heterozygous individuals (ie those with one mutant gene (Fd/fd) also develop the condition but it is often milder (Malik et al 1999, Chang et al 2007, Takanosu et al 2008).

 

How do you know if an animal is a carrier or likely to become affected?

There are no carriers of the gene which are not themselves unaffected: all folded-eared cats develop osteochondrodysplasia to some extent. Cats with normal ears produced from the mating of a folded-eared cat to a non-folded eared cat are genetically fd/fd and do not have the mutated gene or the condition. These cats are called Scottish shorthairs or Scottish fold variants and they do not have SFOCD.

Both Malik et al (1999) and Takanosu et al (2008) recommended that cats with folded ears should not be bred from, whether homozygous or heterozygous. Scottish fold owners have professed their desire to maintain this breed because of its temperament. Malik et al (1999) pointed out that if owners want a cat with a similarly sweet temperament they might wish to consider a Scottish shorthair which differs only in that it is free of the abnormal disease-causing gene.

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But if she is dead set on carrying this through, have the girl x-rayed - this isn't just an ear thing, the painful deformities include the skeletal distortions. This could reveal how many deformed kittens. But suppose all but one are deformed, then what? Seriously?

I'm no expert, not even a layman - just a guy with a science background and google. YMMV

They use fd for Scottish Straight. Both the son and the mother are Folded.  lf the son of the pregnant cat had straight ears, inbreeding aside, the kittens would be normal Folds and Straights at roughly 50/50.

Hmm.  That's odd that you found a site that said all offspring were folds and glad it's not just me that doesn't see how that math would work.  I looked it up on wiki and they seem to agree with the numbers we both calculated (75% fold, 25% non-fold) but if another study's shown that all kittens are folds, I'd like to see their data as I find that pretty unlikely unless they were using homozygotes (which I agree shouldn't be bred).  I wonder if by FoldxFold they were trying to refer just to homozygotes.  Maybe they were noting that they could only come from foldxfold breedings?

And I'm the same.  Not an expert by any means, but I have a science background and google and I do remember working through some problems with fold and manx cats a while back.  I had a professor who really liked cats and used them as an example for pretty much everything.  It was a fun class.

l know, l don't understand the reasoning behind it either, but it's pretty alarming as far as the cats are concerned.

Maybe you would understand this excerpt (l don't), or maybe it doesn't explain what we're trying to understand:

The ears are in the normal "pricked" position at birth but in the folded cat, start to bend forward around four weeks of age. The gene responsible for the folded ears is known as the Fd gene which causes the cartilage of the ear to fold forwards. The Fd is domiant gene with incomplete penetrance. Only one copy of the gene is required for the offspring to inherit the trait. The heterozygous Scottish fold will have one copy of the Fd & one copy of the non-fd gene.

Unfortunately, the gene responsible for the folded ears also has an impact on the skeletal system. Known as "osteodystrophy orosteochondrodysplasia", this condition affects cartilage throughout the body including bone lesions, thickening of the tail, bones in the hind legs becoming thickened and arthritic, resulting in pain & discomfort.

Scottish Folds should never be mated to Scottish Folds as the offspring will be homozygous (ie, have two sets of the Fd gene, making it "double strength", so to speak), resulting in debilitating skeletal deformities.

The dice get rolled anew for each conception.

Yes, OVERALL, a chi square for heterozygous X heterozygous mating will give odds of 25% FF, 50% Fd, and 25% dd However the number of kittens in a litter are miniscule when you are playing these odds. A litter of four kitten COULD come with one FF, two Fd, one dd. Equally possible to get four FF.

Not worth the risk of producing one or more deformed kittens who need to be euthanized at an early age due to untreatable pain.

Thanks for the excerpt.  And I do see what you mean but I think they made a mistake or accidentally implied something they didn't mean.  The rest of the article looks pretty good as far as I can tell, so maybe they meant to say some of the offspring will be homozygous.  From the other information they presented, it does not sound like all kittens should be folds.  It was probably just a poorly chosen phrase.

For the curious, here's a translation of what I think are the technical words in this passage (I'm assuming everyone knows what cartilage is):

Incomplete penetrance- a dominant gene that is not always apparent.  Not all individuals that have the gene will appear to express it, but they may still pass it on to their offspring

Fd/fd- standard notation for a dominant and recessive gene, in this case the gene that is mutated in fold cats

Additionally, back on the topic, I re-read the first post and it sounds like she suspects the cat may be too close to giving birth for a spay/abort.  I don't know her vet's policy, but I know many vets will not operate on animals past a certain point in their pregnancy.  As I said, I don't know much about folds, but if she doesn't have a choice about this pregnancy, does anyone else have any advice on how she can try and make them more comfortable?  My one suggestion would be to genotype all the kittens, if they cannot be aborted, this way at least you know which are and are not affected.  I'm not super-informed on cat pregnancy either (as my only cat is male and will be neutered), so hopefully she's wrong and it's still early enough that something can be done.  If not, hopefully she can find owners with experience with folds who may know some tricks to help manage the pain.

EDIT: And yep, Catapult has it exactly right.

Even this Domestic Cat World site says the same thing. lf it's false, it's quite prevalent:

http://domesticcatworld.com/scottish-fold

Maybe, as you @Artem pointed out earlier, they are referring to the mating of two Folds, whose parents were also Folds, etc. l'm not sure if the OP mentioned if the sire of the male cat in question was a Fold, or if both parents of the dam were Folds.

This has certainly turned into an interesting thread 

Personally, if it were my cat, l would push for abort. Especially since the OP is still questioning if the cat is indeed pregnant. She must still be fairly small.

An easier way of looking at it is single factor and double factor.... two single factor folds (heterozygous) bred together will produce 50% Single factor folds, 25% Double factor folds (homozygous) and 25% non folds. A single factor fold to a double factor fold will produce 50 % of each. And two double factor folds will produce 100% double factors. It's the double factor folds who fare much worse health wise in most cases

I wonder how these kittens went?

Okay but will the kittens be okay? From what I know it would be safer and longer to sadly abort the litter.

Please note that this thread is almost two years old and the original poster has not been on since.

It's the double factor folds who will suffer the most. So fold to fold matings are not a good idea.

bemba said:

 
It's the double factor folds who will suffer the most. So fold to fold matings are not a good idea.

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The thread is around 2 years old.

Yes but the information is always relevant