manx cat with odd "double" tail -- should I worry?

I got my new kitten from a cat shelter, one of a surprise litter of manxes born in the shelter to a normally tailed moggy mum. I had a manx before and he had a tiny, wee, one vertabra stump of a tail. As little Tavy (http://i19.photobucket.com/albums/b193/gneighbour/picstopost/Photo-0007.jpg) has grown bigger it’s evident that he has one of those but also has a little empty bit of tail skin and fur by the side of it, making him look as though he has two wee tails. Does anyone (especially the vets on the board) know if this is likely to be a problem to him in the future?

IANAV, but I’ve had many Manxes, and a few of them have something similar. It never caused a problem. Still, obviously you should mention it to the vet next time you visit.

Side note: You’re neutering, right? Breeding Manxes is animal abuse.

Of course! The money I paid the shelter for him covers a neutering voucher in any case.

Why is breeding Manxes animal abuse?

To oversimplify, most people assume (as I did, before I did some research when I was planning to breed my Manx cat) that there is a gene that’s simply “yes tail/no tail.”

A tail is an extension of the spinal cord. The gene that makes a cat a Manx is the gene that controls the number of vertebrae in the spinal cord. (Again, oversimplifying here.) And since the gene doesn’t have a dial on it or anything, so you can program exactly how many vertebrae to breed for, it’s an inexact science. Basically, you breed for shorter tails . . . until you’ve gone too far. It’s not unusual for the majority of a Manx litter to be destroyed because they don’t have enough of a spinal cord. It’s also not unusual for a “pure bred” Manx (an abstraction; “pure” would be no spine at all) to have limited use of its hindquarters due to spinal problems. This is why some Manx have the “cute” habit of hopping more like a rabbit, than walking like a normal cat. At the time I did this admittedly shallow research (things may have changed by now; I hope so), Manx was the only breed that didn’t lose points in a cat show for incontinence, since it’s relatively common in Manxes. Again, limited muscle control in the hindquarters.

Randomly googling, I find a roughly equal number of sites supporting the above as “debunking” it. Naturally, most of the debunking sites are Manx breeders’.

I wonder if there’s a reliable source for a definitive answer? Wiki’s entry is entirely written by breeders, and mentions the above as a “myth.” I can tell you from experience that if it’s a myth, then anecdotally speaking I’ve encountered a lot of coincidental Manxes with one or more of these symptoms.

Anyway, obviously I need to brush up on my research, but it’s certainly something that anyone who’s thinking of breeding Manxes should look into.

IANA vet but have always understood that tailless Manx cats had a form of spina bifida, hopefully mild enough to allow them to live normally, or perhaps walk with some difficulty but still be able to function as pets. Anyone know about that?

The Wikipedia article says 20% of Manx cats suffer “Manx Syndrome”, which can seriously damage the spinal cord and do other harm; the oldest recorded cat survival with Manx Syndrome was only 5 years.

Right. When I first heard that I immediately spayed my Manx.

My WAG (Ha! I make the pun) is that the second “tail” that feels all soft and squishy either is just an extra tag of skin, like the OP guesses, or, at worst, might be a pocket of spinal fluid that is bubbling under the skin, a form of spina bifida. (technically, we can’t rule out a cancer-like mass, but he’s kind of young for that).

Like other posters have said, manx cats are essentially cats with massively deformed tails. The problems associated with this can vary, and although problems walking, defecating, and urinating are the most common, spina bifida wouldn’t surprise me. I can’t tell from the picture exactly where the tag is, which would help make a spina bifida bubble more or less likely.

If the tag was:
Changing size, consistency, or color
painful
preventing kitty from keeping clean

then off to the vet. If it just bugs you, but doesn’t seem to be doing anything to kitty otherwise, then it’s your call whether you want to fuss with it or not.

Fun genetics side note: Manxism is a single gene dominant trait, meaning that an offspring only has to have one copy of the gene to be a manx (which explains why mom cat had a normal tail). Exactly how much tail grows depends on other genes, but a cat with the manx gene will not have a normal length tail. Two copies of the gene is fatal to the embryo in utero, which is why the trait doesn’t “breed true.”

Pullet
10 months away from being a real vet! But probably shouldn’t be weighing in with her opinion anyhow

Thanks for all the information, and thanks to** lissener** too. Here’s a recent pic which shows the fleshy tail really well. The vertabra tail is just in front (counting his head as the front end). It has a tuft of fur which sticks up when he’s excited but then he won’t keep still long enough to get a good picture of that,
http://s19.photobucket.com/albums/b193/gneighbour/picstopost/?action=view&current=06092008177.jpg

It’s not squishy, or painful or getting in the way at the moment so I’m going to stop worrying and just keep an eye on it as he grows. You mentioned bowel problems and while he’s continent with (very good litter habits he does have a problem with the runs. So long as I feed the chicken rice and white fish diet the vet recommended he’s fine but as soon as he gets into something like the older cat’s biscuits he gets diarrhea all over again. I’m not sure if this is a manx thing or a kitten thing. I’m keeping my fingers crossed it’s the latter, he’s only just four months old.

Edited to add you can see in the picture that the poor thing has feline acne too, but that’s clearing up on his new diet.

Speaking as a former student of genetics and one-time dog breeder of 20 years’ standing, yes, the Manx gene is one which often produces spina bifida. lissener did an excellent layperson’s explanation of the function of the HOX (homeobox) gene and its function. The article on this subject in Wikipedia happens to be one of those that’s decently written, and doesn’t seem to contain any contaminating POVs.

I agree that Manxes shouldn’t be bred for - unless the breeder is prepared to euthanize the kittens with health problems (I do not believe in making animals suffer, and one with neurologic problems has poor prospects for a normal life). OTOH, euthanizing a healthy Manx shouldn’t be done, if there’s a home for it.

Good luck with your kitten, Springtime for Spacers. In your shoes, unless funds are too tight, I’d take him to get that checked, just to be safe. If there’s spinal fluid in that “second tail”, the leak needs to be fixed, or there’s a prospect of injury, followed by serious problems.

SDMB is a community, not just a site with some knowledgeable people. There are a few zillion animal lovers on here who would welcome progress reports, if you decide to stick around.

He’s a bit old for it to be a weaning issue. It’s likey an individual cat thing. Like in people, some critter’s guts just don’t agree with some foodstuffs. Cats and dogs seem to be have the more sensitive tummies of the animal kingdom, but that might be partly because there’s so damned many of them.

Keep him on the diet that works as religiously as you can, and be quick to act if it suddenly stops working or if he turns his nose up at it. That means going to the vet to narrow down what might have changed. And try not to run out of food on a holiday. Prescription foods are a bitch to get ahold of when your vet is closed.

It’s not that big a problem as he’s not on an actual prescription diet. I’m cooking up fresh white fish from my local supermarket in cat milk with a handful of rice, a carrot and a few peas. He’s thriving on it.