American Fancy Rat & Mouse Association

This article is from the WSSF 2006 AFRMA Rat & Mouse Tales news-magazine.

Colors & Coats

Fox Mice & Merle Rats

By Karen Robbins

Phillip Schafer, age 13, Rodent Heaven Rattery, Redlands, CA
Q I have been working with Fox mice for about a month now. I would like a suggestion about what to outcross with besides Fox mice. Would an English Self Blue be a good outcross for Blue Fox mice?

Also, I have some rats I believe are similar to the Hooded Merle that was mentioned in the genetics book by Chris Faron. Except these rats are Capped Merle. I am working on it because it does reproduce, and I hope to standardize it. Can you give me some insight about what this is genetically? Have you seen this before? What is also weird is this is a pattern that darkens with age, and also sometimes new spots form.

A I would recommend you get a copy of the AFRMA Mouse Genetics Book if you haven’t gotten one yet. It has lots of information on breeding different types of mice. If you want to make Blue Fox, then yes, you would cross your Fox mice with a Blue Self and breed the resulting babies to each other. You don’t need to breed specifically to an English Blue if you can’t get hold of one, any Blue Self would work.

Reverse Siamese Fox mouse
A young Reverse Siamese Fox mouse owned and bred by Nichole Royer. He hasn’t developed his “points” yet. Photo ©1998 Karen Robbins.

Chocolate Fox mouse
A Chocolate Fox mouse owned and bred by Albert Collins, England. Photo ©2004 Craig Robbins.

Fox mice may be created in Black, Blue, Chocolate, Dove, Ivory, Beige, Coffee, Reverse Siamese, and Siamese (though would be a disqualification for show).

On your Merle rats, Merle is just the color and they can come in any pattern such as Hooded, Capped, Bareback, etc. These would all be showable as Merle is a recognized color so you would be able to show yours now—no standardizing involved. We’ve had several breeders in the past work on the Merle rats. Yes, the Merle rats will “change” in how the spots show up over time—some seem to disappear and reappear. The darkest spots that show up when they are just getting fur as babies seem to always stay.

Genetically it is a separate gene causing the Merle pattern. Merles come in Pearl (Me- Pepe), Silver Mink/Lilac (Me- Pepe), Mink/Lilac (Me- pepe), or Cinnamon Pearl (A- mm Me- Pepe). *

Merle rat
An adult Merle female rat owned and bred by Carissa Cosley. Photo ©1996 Craig Robbins.

Merle baby rats
Merle baby rats owned and bred by Carissa Cosley. Photo ©1997 Craig Robbins.

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Updated January 4, 2015