American Fancy Rat & Mouse Association

This article is from the Summer 2000 AFRMA Rat & Mouse Tales news-magazine.

Colors & Coats

Making More Odd-Eye & B.E. White Rats; Berkshire Mice?; Making Satin Rats In Other Colors

By Nichole Royer

Making More Odd-Eye & B.E. White Rats

Karl Bailey, e-mail
Q My wife and I recently acquired a female odd-eye rat and were wondering if you might have any insight on what breeding combos are good for keeping the odd-eye trait. We also told a friend that we would try to find good breeding combos for her Black-Eyed White to get more Black-Eyed Whites. Any insight would be greatly appreciated.

A Odd-eyes are one of those funny characteristics that are really hard to breed. You can breed two odd-eyed rats together and get no odd-eyed babies in the litter. More frequently you will get one or two odd-eyed babies. It’s not a simple recessive trait.

Odd-eye Rat

Your best bet (short of finding another odd-eye) would be to breed to a rat with lots of flashy white markings. A Blaze Berkshire, a Capped, or a Masked would be great. We usually see more odd-eyes in the colors that can have either red or ruby eyes, so if you can find a Fawn, Beige, or Lilac, that’s a good choice. In all likelihood you won’t get any odd-eyed babies in your first litter. The best thing to do is keep a promising youngster and breed it back to its odd-eyed parent. That will greatly increase your chances of producing more odd-eyed babies.

Black-eyed White rats are rather tough. Simply put, they are genetically Capped or Masked rats that have been selected for less and less color. For this reason, Black-Eyed Whites often have pigment on their ears and sometimes little patches of color on the fur on top of their head.

I have seen a number of Black-Eyed Whites crop up out of odd-eye breedings, so your friend’s Black-Eyed White might be a good choice to breed your odd-eye to for more odd-eyes. Don’t expect to get Black-Eyed White out of that though.

For more Black-Eyed Whites you will need to find a black eyed rat with very little color on it. Preferably with color nowhere but on its head (and as little there as possible). Breed the two rats together, and keep the babies with the least color. Breed them to each other and back to their BEW parent.

Berkshire Mice?

Beth Signor, Rio Rancho, NM
Q I’ve had a few mice that look very similar to Berkshire (I think) rats; they have a white triangle on the head, white feet and a white belly. What would this be in mice?

A These we see quite often. There is a minor gene that causes a white spot on the mouse’s head. This placed on a Fox mouse gives you what appears to be a Berkshire. Not a recognized variety, but cute all the same. The same gene that causes the head spot can also cause belly spots. Usually, these are true “spots” but occasionally they are large enough to cause most of the belly to be white (particularly if selected for this). If your mice aren’t Foxes, this could be what’s causing the markings.

Making Satin Rats In Other Colors

Q I recently saw a Satin Siamese rat at a show and was intrigued by her. She was very pretty and different. Of course, my first thought was, “Wouldn’t my Russian Blues look great as Satins?” Is this possible to do, and if so, how should I go about it? Also, where do I go to get Satin rats and how much do they cost?

A Though Satin rats are fairly rare, the Satin trait is a relatively simple one to work with. It produces rats with long fine hair that is shiny and rather different from that of normal-coated rats. The coat sometimes looks like it has been greased, and any white areas on the rat appear yellowed. The entire rat is shiny including the belly (thus differentiating Satins from dark shiny normal-coated rats). Unfortunately, they are not as distinctly “satiny” as Satin mice, instead more closely resembling Satin dwarf hamsters.

Satin is a simple recessive. That means that in order to produce Satins, both parents have to either be Satins themselves or be carrying the Satin gene.

Currently, Satins come in a small number of colors. Russian Blue isn’t one of them; however, Russian Blue Satin would be simple to create.

The first step would be to get a Satin of any color and breed it to your Russian Blue. Keep the nicest male and female baby out of that litter and breed them together. About one-quarter of the resulting litter should be Satins; however, sometimes the genetic marbles don’t fall in the right holes and you get a fewer (or greater) number. You may have to repeat this breeding several times in order to produce Russian Blue Satin.

This breeding should also produce Russian Blue normal-coated babies. If you breed these babies together (or back to their parents), you will also increase your chance of producing Russian Blue Satin.

As I said before, true Satins are rare. All that I know of in the United States are out of Karen Robbins’ lines. There are other rats that people call Satins, but often they are simply dark rats with nice shiny coats. If you are buying a Satin rat, ask about its background and request a pedigree. Typically Satin rats are fairly expensive and breeders are picky about who they sell to. This is not so much a desire to make a profit off of them as it is an effort to keep them out of the hands of breeders who will breed them indiscriminately. This is one variety we would rather not see ruined by the commercial pet industry. *

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Updated December 28, 2014