# What's a "High-White" Marking?



## CosmicKat62 (Nov 24, 2014)

I was reading the megacolon thread and I'm just wondering exactly what is a high-white marking. Just out of curiosity, all my rats are fine.


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## DustyRat (Jul 9, 2012)

High white are rats that have a certain amount of white coloration that may point to megacolon. A rat with a totally white cap Is considered to be high white. There are other color combinations as well, but I am not certain of what they all are. But mostly white around the head is considered to be high white.


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## CosmicKat62 (Nov 24, 2014)

Oh. Thanks!


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## Rat Daddy (Sep 25, 2011)

Actually I look for the white to run up the flanks and thighs on a rat where the white should only be on the belly. Sometimes you get a large badger blaze or a lightening blaze and sometimes you even get a pretty cool Dalmation or almost tiger pattern (I've only ever seen one). 

All of the high whites I've seen have top ears, but I can't say it's a rule for sure.... Most high whites are really unique looking and beautiful making them highly desirable. On the other hand once you have lived with one, you realize it's subtly off... Nose too long or feet too big, fur an unusual texture, a subtle asymmetry in the markings etc... The whole animal is just slightly off. It really is hard to describe, but with experience you just know one when you see it... It's almost just like a normal rat, but it isn't... sometimes it's a combination of subtle features. And sometimes it can be hard to be sure without seeing the whole litter or at least a few siblings or the parents.

Amelia was our high white... we found her culled into a feeder bin at a pet shop by a "reputable high white breeder" that seemed to dump surviving pups of litters gone megacolon and even used up breeders there. She grew up to be magnificent.









Notice the slightly asymmetrical blaze, the long snout and the white feathering on her flanks.... Her feet were also huge, her fur was hard and wiry and she grew up to be huge... I might add that her white fur had a bluish tinge and her black fur was more of a very dark brown.

If you held her and you have handled a lot of rats it would take you about 30 seconds to pick up that she seemed "wrong"... It's like a feeling you get... and that's pretty much how you know a rat is high white... If you drop a single high white in a bin with 50 other rats it's the one that stands out, it's like obvious, but you can't entirely put your finger on why. To really stretch my example, think about downs syndrome. There's noting particularly different about down's syndrome humans from other humans, but you recognize it most of the time when you see it. In rats it's a particularly attractive genetic variation... so people are always going to breed high whites, unfortunately, so far there is no megacolon safe variant of he American high white. After they are about six weeks old and healthy they are usually safe to own, but they are never safe to breed.

I might note that our part wild rat came out of the same feeder bin as our high white... and before that pet shop closed, they had a few smaller high white wet nurses. I'm just guessing, but the breeder might have been trying to interbreed high whites with part wild rats. So I tend to believe that there are still breeders trying to correct the megacolon issues, but I'd be very skeptical that anyone has as of yet succeeded.

They are great rats to own, and very dangerous to breed.

Hope that helps.


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## CosmicKat62 (Nov 24, 2014)

Thanks Rat Daddy, that cleared it up a lot.


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## Rat Daddy (Sep 25, 2011)

Just to add a little clarity or confusion, these rats aren't high white:








Cloud is a dumbo, blue, silky rex with a lightning blaze.... she has traits common to high whites, but if you look carefully, she's pudgy, but otherwise normal.











Misty, next to Cloud is a blue caped silky dumbo, with black ruby eyes, yes her cape feather's down on her sides a bit, but her blaze is of normal size and it's a matter of her cape being a little feathery not her belly white creeping up her sides... again her shape is normal.

My 9 year is pretty good at spotting high whites too... I think she looks for the gleam in my eyes when I see one.... Yes, I know... it's so wrong to breed these rats, it's so not to be encouraged... but I have such a soft spot for these tragic little beauties... 

When we first saw Amelia as a 3 week old pup, she was bespoken by a pet shop employee and not for sale.... and my daughter rightfully pointed out she was high white and we didn't want a rat that might get megacolon... pretty smart for a 6 year old... Six months later, the girl that adopted Amelia didn't want her anymore... I don't adopt 7 month old rats. But because she was high white I met her anyway. We had Fuzzy Rat along, and Fuzzy Rat immediately approved of her, right in the parking lot, she sniffed Amelia and gave me a big kiss, and my weakness for high whites kicked in... Amelia was neglected and never became a true shoulder rat, but we loved her a great deal, she was smart and lived to two years old and died of a single large mammary tumor, that might have been operable. 

On principle, I don't encourage anyone to support the breeding of high whites, in practice, I have a lot of trouble resisting them... and when we did take Amelia outdoors, she instantly attracted crowds... people instantly fell in love with her looks... She hated the attention, but people instantly felt at ease with her because of her markings. Even people that don't like rats respond to high whites differently... there really is something about that slightly one off look that makes high whites look and feel different...


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## moonkissed (Dec 26, 2011)

High White can refer to two different things so it is a bit complicated as both are used. Some only use it to refer to the rats with genes that can cause MC but other people use it for all rats with the high white markings. 

I am going to have to disagree with Rat Daddy here... there is not going to be anything noticeably different about a high white rat vs any other rat. They can be any ear type too. High white just refers to markings, in the simplest terms it just means alot of white. They are a normal rat. You see it in huskies, BEW, dalmatians, split capped, blaze, Odd Eyed. High White is nothing more than a classification of markings or genes. It means nothing more. The size of the rat, the shape of their nose, size of their features, and coat type have nothing to do with their markings.... 

High White rats are genetically at a higher risk for megacolon. But not all high whites get it. And non high whites can get it too. It depends on the genes and it occurs during the embryo stage so it may not occur always. You will usually see the signs of MC at about 3 weeks old or so when they begin eating food. It is possible to have late onset MC but as far as I know it is quite rare.

The truth is megacolon is very complicated. it is not easy to explain. And in truth high white has become very misleading because it isn't exactly those markings themselves but the genetics. It is very possible to have high whites that are bred from the recessive genes or safe sox10 and some breeders have done this. But it takes a very experienced and well kept history to do so. But it is also the #1 reason why i stress ppl should never breed without knowing the history of their rats, because it can pop up and it is a horrible thing to put a baby through 

here is a link on megacolon:
http://ratguide.com/health/digestive/megacolon.php
http://www.ratbehavior.org/megacolon.htm

here is alittle bit about white markings:
http://www.curiousv.com/curiosityrats/files/geneticsmarkings.html


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