High White?

[Michelle.C]

Huh?
High white is a term for the gene not the amount of white on a rat?
A high white can be a hooded rat that has a head spot, it can be a berkshire with almost no white on the belly but if it has a head spot it's got to be considered high white.

I've always been told if a rat has white where it normally wouldn't be then it's caused by the high white gene.

Hooded rats are not high white and neither are berkshires or selfs unless they also have a blaze or a head spot or in the case of a hooded if the stripe is broken and white goes across the back

Agreed. High white is actually a misleading term. A rat can be 99% solid black with one tiny head spot (thus it being called the "spotting" gene) and it be high risk for megacolon, etc.

To the Op, High white or the "spotting" gene is where the rat is actually a solid color and it has white where there isn't supposed to be any. Such as blazed, capped, banded, variegated, dalmatian, etc.

Also, if you are wanting to breed high whites, just breed them to a solid colored mate. They will still likely throw attractive blazes, etc. If they don't, you have a recessive marked line which is considered a little safer to work with. That being said, I have a friend who works with proven megacolon rats but doesn't produce any due to selective breeding.

You can also post a picture up and someone on this or another rodent savy forum will be able to help you with the markings. If you don't know the genetics, assume it's a risky line and breed to self (solid colored or hooded) mates. Later if you want to find out if you have a line that has megacolon, breed two of the high white siblings together.