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Discussion Starter · #1 ·
Dominant manx is a rare variety in the US that I've bred since 2007. My original stock were very poorly-typed and while I'm currently not where I want to be with them, I've made great improvements. Here is a photo of one of my PEW bucks and a video of my daughter holding both a manx and a tricolor. In the ECMA, manx are shown in the unstandardized classes.

http://www.onetruemedia.com/otm_site/vi ... kin_id=601



I know that manx is frowned upon in Germany, and relatively common in Australia (recessive form), but I wonder: how common (or uncommon) is manx in the UK?
 

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Manx cats are little walking disasters, so I would hope it's not the same mutation in mice.

Most people don't know that the Manx gene in cats doesn't just cause the cat to be tailless. The Manx gene in cats effects multiple sections of the axial skeleton. In addition to the obvious differences in number and size of the coccygeal vertebra, there are also documented differences in the sizes of the cervical, thoracic, and lumbar vertebra, as well as changes in the shape of the pelvic and sacral bone structure.

I've got a house full of unadoptable Manx cats with a variety of spinal, orthopedic, urinary, and intestinal issues. In the last 6 years, I've spent well over $15,000 just on surgical interventions, to bring them to some reasonable level of comfort and health. I have one Manx cat that is missing his entire xyphoid process, several ribs, and a large portion of his sternum which leaves his lungs unprotected. He has to wear a special "vest" with fiberglass inserts to replace those missing bone portions.

In my lowly opinion, Manx cats should no longer be purposely bred. At this point in time, there's too much damage to the gene pool and no responsible way to correct it. For example, until the early 1980's, the breed standard listed a "hoppity gait" and desirable, so breeders bred and bred and bred with that as a goal. In 1979, a study was published that confirmed that the gait was actually a result of a syringomyelia and only then was the "hoppity gait" removed from the standard. But by that time, breeders had spent literally decades purposely breeding health out.

Breeders can achieve the same aesthetic in cats, using alternative genetic means that don't carry the orthopedic and CNS dangers that come with the Manx gene, so I see no ethical justification for breeding cats with Manx gene. But I'm a lot more opinionated than most on that topic, because I've spent more time (and money) than most dealing with the aftermath.
 

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There are two types of Manx, the one in Australia is recessive and I don't know what, if any, health problems may be associated with it.

The ones in the U.S. are dominant and can vary from an almost full length tail to no tail. Unfortunately, this does require breeding Manx to Manx, and you can get mice with some drastic negative health side effects (like being unable to use its back legs) in the process. These are, typically, culled out. I had owned/bred Manx about 7 years ago, but I did not like the variety very much and stopped the breeding program after the first year.
 

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Discussion Starter · #10 ·
nuedaimice said:
There are two types of Manx, the one in Australia is recessive and I don't know what, if any, health problems may be associated with it.

The ones in the U.S. are dominant and can vary from an almost full length tail to no tail. Unfortunately, this does require breeding Manx to Manx, and you can get mice with some drastic negative health side effects (like being unable to use its back legs) in the process. These are, typically, culled out. I had owned/bred Manx about 7 years ago, but I did not like the variety very much and stopped the breeding program after the first year.
I'm sorry to be blunt, but you're wrong. :cool:

I consistently get fully tailless offspring from breeding a pure English 100% NON-manx crossed to a manx mouse that has even up to a half tail. Half tailed manx X fully tailed non-manx line does produce full tailless manx mice. I actually need to produce a manx male that has a partial tail but can't seem to do it. They always turn out fully tailless for some reason. The fully tailless males have trouble breeding because the angle of their pelvis prevents their penis from going the proper direction to penetrate the females, which is why I need a male that has a partial tail. However, my fully tailless females have no problems becoming pregnant or birthing babies and have been great mothers.

I've never had a manx mouse who could not use its hind legs nor have I ever had a manx mouse with incontinence issues or anything like that, even when breeding manx X manx. I've been breeding manx mice since early 2007.
 

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Congratulations on coming so far with them then!

I knew of a couple of U.S. Manx breeders who had told me they had such issues breeding Manx to Manx, as well. It can be very common in any animal with a dominant tail shortening gene, since the gene is removing vertebrate from the tail, its very easy for it to remove vertebrate from the spine, as well (typically fully tailless animals do have a few vertebrate missing from the base of the spine).
 

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Discussion Starter · #12 ·
Thank you! But honestly, I have not needed to select against any health issues at all because they just were not present in this line. The progress I've made regarding type is very evident, though. The manx mice I started with had extreme pet type. They were small and cobby with tiny ears and all sorts of recessives.

Which US Manx breeders told you they had issues breeding manx X manx? I'm curious. :p If you don't want to post the names on the board, you may send me a PM. (BTW, I received a notice that you had sent me a private message 2 days ago but it said you deleted it before I could read it. What did it say?)

If it were "very common" to have issues of the spine in manx mice, it seems I'd have seen some sort of issue in the 3+ years I've been breeding them. Maybe I've just been lucky?
 

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nuedaimice said:
(typically fully tailless animals do have a few vertebrate missing from the base of the spine).
Not to be too much of a stickler, but proper terminology might help keep things straight.

In properly bred tailless animals, -only- coccygeal vertebrae should be missing. Those are the vertebrae of the tail. The vertebrae that are at the base of the spine are lumbar vertebrae, and those should -not- be missing. Missing lumbar vertebrae are referred to as a "negative tail" and missing vertebrae in that area causes the neurological issues. And that's something that I do know is consistent across species, including humans.

WNT, what you've described with breeding your mice to non-Manx English mice and having no-tail to long-tail mixed in the litter is also true with cats. Crossing with other breeds would be a way to breed registered Manx cats back to health, but the CFA disallows outcrossing to other breeds, so they leave Manx breeders no choice but to breed only Manx to Manx, which just moves the breed further and further away from health. When breeding Manx to Manx, about 25% of the litter is either stillborn or dies and is reabsorbed as a result of the lethal double dominant Manx gene (M/M); 25% of the litter has a full tail (m/m); and the remaining 50% of the litter is composed of the variably expressed tail lengths (M/m). They can range from missing a single coccygeal vertebrae (technically a "longy" but often categorized as "tailed" if there's no radiological examination) to missing all of the coccygeal vertebrae (classified as a "rumpy").

Because of the way the gene behaves in cats, you can't predict what tail length you'll get based on what the parents had. The unpredictability of your tail lengths sounds very similar to the mutation in cats and as long as you don't breed to the point of having the "negative tail" (removing lumbar vertebrae in an effort to get to breed rumpy to rumpy, trying to get full litters of rumpies, which cat breeders have already proved doesn't work), I suspect you'll continue to have healthy mice and not show those undesirable spinal and neurological effects.

With that said, there is something else that rings similar in cats to what nuedaimice said about the Australian recessive mice. Japanese Bobtail cats have a recessive tailless gene and American Bobtails have a dominant tailless gene, with neither breed having the Manx gene involved. Neither of those breeds show the major negative spinal and neurological effects associated with the Manx gene and both being more stable and predictable as far as the length of the tails.
 

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I had a couple of rex manx when I lived in Australia and bred them. They were very cute. I live in England now and haven't seen any here. Along with brindle.. But the colours and varieties here make up for the loss of those two. :)
 

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Rhasputin said:
It makes boys look pretty funny . . . :lol:
You think that's bad, I have a manx rat and he has huge ..... danglys :shifty
I've read there are all sorts of ethical issues surround them too but for what it's worth my manx rat lives a completely normal ratty life. He's just not too good at climbing things.

I love my manx mice and they can climb as well as any tailed mouse can. My specialty is longcoat rex (texel) manx.
I'm in Australia, we only have recessive manx. Manx are fairly common (not too many being shown at the moment) but usually have a tail stump.
I've got 3 pinkie manx at the moment who were the result of pairings by carriers. I was hoping for more ... I got ripped off!

It's not recommended to do a manx to manx pairing. I'm not sure if it has any negative impacts, I've never tried it.

One breeder had difficulty keeping her manx alive in her litters. I don't know if it's in relation to the manx tail or something else.

Manx is a physical deformity that can have the potential for health issues, like brachycephalic dogs.
Most examples of manx I've seen seen in good health, it doesn't effect their mobility.

I generally prefer not to breed from manx females if possible due to increased risk during birth. Although, I have used a manx female (with tail stump) and she raised a litter fine.
 
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