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Megacolon the dreaded genetic disease...

51K views 33 replies 17 participants last post by  Carpenters4522 
#1 ·
This is just an informational post on a dreaded genetic disease. Some people may never have heard of it, but the ones who have experienced it will never ever forget it. :(
Genetic megacolon occurs as a result of faulty cell development in the embryo stage. The nerve cells in the wall of the colon and/or rectum are either missing or are non-functioning in affected animals. These nerves are necessary in order to move stool along and out. In rats, this means that the stool will back up, and they will bloat. This is most likely painful and eventually results in the death of the animal from malnutrition or bacteremia. Though this condition can occur in any rat, it is very often seen in rats with what are called "high-white" markings. The same relationship occurs in a certain type of Waardenburg syndrome in humans where there is either odd-eyes or a white patch of hair or pigment accompanying the digestive involvement. Lethal white foal syndrome in horses occurs in the overo types (white or mostly white) and causes death from megacolon within a few hours or days of birth.

From ratguide.com
Megacolon can be either early or late (delayed) onset.
With early onset megacolon the signs will usually begin to show as soon as the baby begins eating solid food (around 2 weeks) although sometimes it is not apparent there is a problem till they are 3 or 4 weeks old. Some babies will show a distinct failure to thrive even though they are eating well. This occurs due to the lack of proper absorption of nutrients in the damaged digestive tract. Early onset signs such as bloating, diarrhea, and severe constipation typify the quick advancement of the disease. It is recommended to consider euthanasia rather than to let the disease follow its ultimate lethal course.
Late, or delayed, onset megacolon appears to have the same genetic origin as early onset and is seen in the same lines as early onset. It may be a milder form of the disease, but unfortunately it does progress in severity until it becomes lethal. Often the first sign of delayed onset megacolon is shown by the baby rat’s failure to thrive. Gastrointestinal problems may not become apparent until the rat is 2-5 months old. At that time you may see bloating, diarrhea, constipation, or alternating bouts of diarrhea and constipation. Stools passed may be hard, fibrous, foul smelling, dry, oversized, oddly shaped, blunt on the ends, and have blood or mucus in or between them.
Late onset can also be even more delayed, sometimes not becoming symptomatic until the rat has reached a later age of 4-10 months. With no early warning signs of a problem (such as failure to thrive, unusual stools, or chronic diarrhea) the very late onset type may often be too far advanced, by the time the owner notices a problem, to treat.


2 case histories of early onset megacolon

Health Guide: Megacolon Figure 1c
Health Guide: Megacolon Figure 1b

Late onset megacolon

Health Guide: Megacolon Figure 2a

And here is the wonderful article on high-white rat markings and how to determine high white (lots of cute baby pics too as well as comparison marking pictures)

http://www.midwestrats.org/articlehighwhitecont.html

Just remember not to even contemplate breeding those cute odd-eyed blaze rats you may have, as you could be dooming them to a fate just like Lil'Bit's. :(

http://www.paw-talk.net/forums/f16/the-story-of-lilbit-why-not-to-breed-43986.html
 
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#6 ·
Thats very helpful! Thanks for posting!
 
#8 ·
wow poor little rats. i get backed up sometimes lol....... I dont think im gonna have that problem cause i have no rats but cool info for you rat lovers..... on that note i think i need an enima...... he he
 
#13 ·
Does this help at all?

White Spotting Gene (aka: American Husky, High White, Aurora)
Anyone choosing to breed any rat that carries the white spotting gene should be familiar with megacolon. Megacolon is a symptom of the white spotting gene forming at a poor time during fetal development. Megacolon (MC) forms during the fetal development of the neural crest. This interference causes the nerves that serve the colon to not develop properly or incompletely. A kitten with MC will or may appear normal until weaning or starting solid foods. The symptoms develop between 3 and 6 weeks (average). Symptoms include bloating and intermittent diarrhea. There is no known treatment that stops it from happening.

Do some research on these as well to see if you get your answer (sorry I am at work :p)
Genetic aganglionic megacolon in rats is a congenital condition similar to Hirschsprung’s disease (in humans), lethal white foal syndrome (in horses), piebald related megacolon (in mice), and some types of Waardenburg syndrome (in humans).
 
#10 ·
does anyone know if this can happen to mice as well or just rats?
 
#22 ·
I had posted before in another post about Megacoloen which is on Blazed or wedged faced rats. High whites yes as well for mice its a color called lethel Yellow which is hard to tell from safe yellow which the only way really is to watch them when they reach 3 to 4 months old Lethel yelow will get big almost prego looking becuase they can develop thyrodie and diebeties among other things. Some dont show a sign and sometimes you have to breed to find out if they all are yellow or most the litter then that could very will be a lethel yellow in mice. but there are soem health probelms with mice that you can not cure but they can taek meds for.
The rats with The white plaze I have a few and have breed some. My 1st were 2 blazed faced before any breecers or anyone told me about mc all are 7 months old and doing well but I was lucky no one had probelmes. If you have a blaze fcaed rat or hight white and you do breed it breed it to a solid or a hood that had maybe a spot on the head or none at all. Blaze faces come up in lines and litters so if you breed and they all have blazes you might want to maek shure that line is ok. There is one breeder out in LA that breeds the patched and blazed rats but she carfuly pics out the blazes to breed. I breed blaze to plain or solid or hoods but not a blaze to a blaze unless I know what is from the family back ground.
Not all of them have it in PA here we never head of it and have only had a few cases from a couple tha thad gotten rats of of poor breeders or feeders. or moved here with them.
Go to meet up groups to the New yourk city Rat meet up you'll find Raquel the moditrater She can tell you the indepth of Megacolen I know she has a artical some were or I can see if she can send it to me and I can post it. Which exspalines every little detail to a t. or send me the link to it. I use to have it but cant find it. the AFRMA may have stuff on the mice if you want to look them up for those of you that have mice. I found my info on the fun mousery then just sertche dhte web for more infor on the subect of Lethel Yellow and other stuff.
This is not something that is new its been around for a while Raquel told me that she has known about it for a while but its becomeing more and more aperent. Look at my site and my Blazed faced rats they all are fine and no probelm but if and when breed get breed to a rat that has no blaze or dont have to many blazes that have showen up in the litters, as in in the back ground. There is some breeders that are focusing on the blaze faced and high whites to breed the problem out of them so this way they are not suffering. And they can pinpoint were, how and why this probelm has ocured and what can be done to avoid it or get it out of the lines.
BUt thank you for posting it. I did nto relized that there were so many others that didnt not know this like me when I 1st started out.
http://theratpack.webs.com
also on there is a link to the AFRMA at the bottom of the home page I think they also have info on the subject.
Diamond
The parents are below but they only had 3 babies with blazes only 2 are shown on this pic the other blazed in Tattioe but she is alco considered a miss marked patched rat. and taj is missing he ha a head spot. ps the one with the name shina turned out to be a boy his man hoods droped late.


 
#23 · (Edited)
ok so I have a question.
Is late-onset megacolon fast or slow growing?
If i post a picture on here of a rat, are you guys able to tell the difference between a fat rat and a megacolon rat?
.
I think my friend's rat might have late onset rather than be obese because i noticed that in the time span that louna had time to poop 3 times, she only pooed once, and the poos are twice the size of louna's and pretty dry.
I'm gonna watch it over the next 5 days, because maybe she's just toilet corner shy since she doesn't know my place yet and doesn't feel at home.
 
#25 ·
she just feels really bloated compared to louna, with her skin not too tight around it, but it's kinda like a water balloon or something.
My camera is all out of batteries, but i'm charging it tonight and will post pics tomorrow!
I'm gonna feel her again to make sure, seems like today she pooped a little more but i gave her some veggies last night which she doesn't get too much of. (she is VIOLENT to get the veggies out of my hands compared to my gentle louna!)
 
#27 ·
she's just over a year old, and she has been this fat without worsening since more than 6 months.
I saw her when she was just 2 or 3 months old, and then I didn't see her until august 2009, where she was really fat already. So to me she started being fat when she stopped growing, and she had a tiny tiny cage so I thought it was lack of exercise.
.
I felt her belly again, and it just feels bloated, no hard lumps, and she poos ok in the end, less than louna, but she doesn't seem blocked.
However, she doesn't eat that much since a while because my friend started rationing her portions, and doesn't give her any sweet or salty treats. She has had a bigger cage for a month or 2 and still, no weight loss.
I don't know how fast it's supposed to go with rats.
 
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