Intensively inbreeding for cuteness?

[squidpop]

Well, this is interesting. I've got some sources on megacolon and links but none of them say anything about the prevalence of megacolon in Charlies, whether its 50% or 100%. What Rebel Rose and Akane wrote shed more light on how common it is, than anything I've read.

What Rebel Rose wrote was interesting because she said some lines don't carry it, but I wonder if there are more genes, besides EnEn for spotty rabbits and charlie markings.
I remember Dood said on another forum that Hot Tots do not get their markings from the English Spot gene, so they don't always have megacolon. So that makes me think there is another gene that creates Charlie markings besides EnEn which might explain why some people breed all Charlies with no problems.

From the pet forums I have read, they say a megacolon rabbit is hard to keep alive for more than 4 years. I have one that is going on 2 years, he seems healthy, He just has random big oval poos mixed in with regular poos, but I've heard this gets worse over time. I've read that sometimes megacolon kits are more likely to die at weaning age.

Here's a link to a scientific paper about it: http://www.medirabbit.com/EN/GI_disease ... acolon.pdf
and how to identify megacolon https://www.facebook.com/media/set/?set ... 058&type=3
On pet forums there are lots of people trying to keep their megacolon pet bunnies alive, which is a bit sad. http://www.rabbitsonline.net/f27/megaco ... ase-30046/

Maybe it would be good to post on this forum about Megacolon and ask others what their experiences are.

 

[Prisma]

Very interesting, trying to remember if I've ever seen a magacolon issue posted on a breeder group and there's not any I can recall. Maybe it is some lines issue, I never thought of it that way before, just know about it with the BEWs. Not saying there hasn't been any with some breeder some where that breeds for primarily show, but I would think if it was as big a problem as some of the links suggest (also did a general google) then it would be more commonly found and asked about. Every page I've looked at has some thing to do with rescues/shelter/pet rabbits although I did see on the one where Pam had posted on a posting on it.

With my original MR and HLs, that was in 2001 and sold all relations I had left in 2012/2013....I would've thought if it was going to crop up it would've during that time period as I kept several and never had a complaint on charlie marked ones. I did have broken and solids concerns over those years, but those were related to the care they had with poor housing, handling, and food issues on the new owners parts. One questionable issue, but it was a solid doe that the new owner failed to even contact me about having had an issue that I found out about almost a year later. I would never sell (or breed for that matter) a rabbit that I thought was responsible for a medical problem, even just a carrier, no matter how nice of a rabbit it was or how expensive it was for me to get.

The other person has not had issues for the entire time has been breeding to the best of my knowledge and we talk quite a bit, very rarely sells any thing and then from what I know only to those has close contact with, here lately that's been a little different as they've branched out into another breed and has sold more to those that there's not as long knowing the person. I've never heard of their rabbits having issues or having had issues in the past, I know they've had rabbits before I had mine but how far back I have no idea and haven't asked. They did have an issue with feed/strange illness about 2-3 years ago (might not have been that long ago but it seems that way), but it didn't matter what breed/color it was and the problem seemed to resolve itself after it went through. Would be interesting to see a study, if I happen to find one will post. <br /><br /> -- Wed Jun 04, 2014 6:43 pm -- <br /><br /> I guess there was some confusion when I said I'd heard of it before, meant the some charlies dieing off.

 

[akane]

It probably comes up less with breeders because most don't keep rabbits that can't be shown for a long period of time. Some do rely on their original stock for as long as possible if they are keeping their numbers low and more often if they are breeding for meat. Most I've met make use of the genes and move on to the next generation with often only some really good foundation or early stock being held on to for longer than a few years. I haven't actually heard of anyone keeping a charlie for long term breeding of brokens despite many saying it could be useful. It makes it as hard to establish a good pattern as throwing in solids with unknown modifiers. You can't see the quality of the modifiers on the pattern. A well patterned broken to another well patterned broken or to a solid with a well patterned broken in it's background is preferred instead of solid to charlie. Too much mystery in what you'll get. Also again even those who do decide to keep a charlie for crossing to a broken or solid is less likely to keep it past a few litters and then replace with a nice offspring or new stock because the offspring aren't good enough.

Pet owners will keep the rabbit for years and possibly it's entire lifespan so are more likely to see health problems.

Another factor is that pet people are more likely to take sick rabbits to vets and try to save them with long term illnesses. A breeder who has a charlie get sick here and there will probably write it off as the odd GI issue you can get with any rabbit and put the rabbit down once it doesn't respond to basic treatment. If you only keep 2-4 charlies for breeding more than a single litter over several years and half get megacolon that's only 1-2 rabbit deaths. Not much to build a hypothesis on. The charlie culls that are being sent in to the pet world, taken to vets, reported online with problems, and treated for years are going to get a lot more attention.

 

[squidpop]

I don't think a lot of people who have megacolon rabbits know what is wrong with their rabbits, because they are usually healthy up to 2 years, like what Akane said, except their poo is oval and larger than usual, but they aren't necessarily sickly... that comes later. I did a lot of reading when I got my first spotted rabbit, about breeding (En en) genes, and none of the sites said anything about megacolon, so it would be hard for a regular pet owner to ever figure out their charlie has megacolon. I noticed my rabbit had big poos but only realized it was because of megacolon because I happened to read a post about megacolon on a pet forum.

I think it would be hard to determine what percentage of rabbits that are charlies also have megacolon because you never know if a pet rabbit is a true charlie or a false charlie. So a rabbit that looks like a charlie, and doesn't have megacolon, could be a false charlie. Maybe charlies that are a combo of Dutch and (En en) don't get it. <br /><br /> -- Thu Jun 05, 2014 1:25 am -- <br /><br /> I think I got the answer. It sounds like its not as common as I was thinking. I emailed Dana Krempel, the phd that writes for the house rabbit society. She wrote back:

Not all "charlies" have the congenital failure of their melanocyte neuron-precursor cells to properly migrate and innervate the gut. It's a polygenic condition, and also possibly influenced by in utero environment. In short, the actual developmental mechanism isn't fully understood.

I would say the vast majority of "charlie" rabbits do NOT have the condition, though. It's not all that common. But it's awful when it does show up.

Dana
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dana Krempels, Ph.D. ^
Senior Lecturer, Director of Undergraduate Studies ^
University of Miami Department of Biology ^
[email protected] ^
^
Compassion towards animals is essentially ^
bound up with goodness of character. ^
Whoever is cruel to them cannot be good to men. ^
-- Arthur Schopenhauer ^
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^

 

[Kyle@theWintertime]

I'm glad you looked into it further because, if Charlie = MEGACOLON in the majority of homozygous broken rabbits, I felt pretty sure we'd have all heard about it before, similar to the well-known and well-documented issues of merle-to-merle breedings (homozygous merles) in dogs. I have heard anecdotal health issues with Charlies but I've also had other people tell me they have Charlies who are just fine, so I figured mileage may vary.

What I was hemming and hawing about pointing out is that I'd already posted this earlier:

This is rapidly becoming a moot point...Tionol has started turning on her kits, growling and boxing them when they wander too close. I do believe mothering is a somewhat genetic instinct and I'm pretty angry and disappointed in her. I don't want a lineage of bad mothers. I might keep one of the cute baby bucks to breed to my MR does (maybe my MR can pay their feed bill with producing cute pets in between purebred litters for ME) but forget keeping a buck AND doe kit. Putting a buck from a bad-mother line to a doe with great instincts is one thing, putting two rabbits of a bad-mother line together seems to be asking for disaster.

In other words, before you went on about Charlies = megacolon, I'd already opted NOT to keep a doe kit at ALL, ergo no possible Charlies.

BUT, I'm not too upset by thread hijacks, and was more curious about where your information was from.