American Fancy Rat & Mouse Association

This article is from the WSSF 2012 AFRMA Rat & Mouse Tales news-magazine.

Colors & Coats

Essex Roan Rats; Roan or Merle Rats?; Chinchilla, Roan, or ?? Rat; Chinchilla Rat Genetics

By Karen Robbins

Essex Roan Rats

Barbara Reed, Greenbrier, TN
QAre Essex rats recessive or dominant? I have been looking on many sites and I am not finding this out. Also, can Roans be Essex? Amanda Lacy, Rattie & Mattie’s Rattery, AZ

QCan Essex still be carried if a rat has an Essex parent? Amy, Camarattery, CO

AEssex is dominant and not a marked gene. When bred with solid/Self you get Essex and Self. Go to to see the standard. The rat has to be it to produce it, just like Rex. So, to get Essex kids, one of the parents has to be Essex. The non-Essex Self kids will not throw Essex unless bred to one.

Since Essex is not a marked gene, when bred with a Self you won’t get varying amounts of white markings like when breeding Hooded or Berkshire to Self. There was an article on Essex by Joanna Holmes in England (you have to see an archived version now).

In regards to Essex Roans, I would suggest contacting the National Fancy Rat Society to see if any of their Essex or Roan breeders did this combination. The N.F.R.S. is on Facebook or go to their contact page for e-mail addresses.

I don’t think this would be something good for show as it would be hard to tell fading of the Essex when Roans get lighter with each molt and some turn into an almost white rat.

You can read more about Husky/Roan rats in the articles by Sue Brown, England, and by Pirjo Pipsa Mankinen in Finland.

Roan or Merle Rats?

Kelly Winter, U.K., e-mail
Ophelia QI have recently rescued four female rats, and I am baffled as to what colour they are. I have attached some pictures of them to help with identifying the colours. Three of them look like Roans/Huskys but their colour is mottled. I have owned a Striped Roan before and his colour was perfect all the way through. Also, the lighter coloured one is mottled too. If you have any idea or can help identify their colours, I would be very grateful. Thank you so much in advance.


AIn your photos they do indeed look like the Roan rats and have the typical Roan pattern, but the black spots mixed in make them look like Merle rats as well. Since you just got them, wait a few weeks to see if they keep this color pattern or if they eventually even out in the color. If they even out in color, then they are molting very strangely. If they keep these spots, then it would indeed be some kind of strange merled roan color. Merles normally are found only on Mink/Pearl colors and three of your four rats look like Black Roans (the fourth one that is light colored, I can’t tell what the color/pattern/marking is). Since you have had Roan before, you know about the gradual lightening of color with each molt.

Chinchilla, Roan, or ?? Rat

Carol Lawton, Blue Shuze Rodentry, CA, e-mail
Blazed Berkshire rat QI just got this rat from the pet shop and was wondering if it was Chinchilla or Roan?

Update 2 weeks later: I’m still not sure about this little male rat that I have—he doesn’t really look like a Blue or a Roan, but he’s developing odd light and dark patches in his coat.

AThis doesn’t look like Chinchilla—too Blue and I don’t see Agouti type hairs. He has the typical pattern seen in Striped Roan rats and by his color he looks like Blue of some kind. Roans start out a solid color then get silvering with each molt. Since he has baby coat, I can’t really tell if his color is solid or silvered already. He could also be just a Blaze Berkshire that has too much white running up the sides. I would have to see more photos to be able to tell what could be going on with the light and dark patches.

Chinchilla Rat Genetics

Van Chartier, LovinDaRats Rodentry, CA, e-mail

QThis is Van from LovinDaRats Rodentry again. I was checking through our Cap-Stripe’s genetics and I happened across the NFRS’s studies on the Chinchilla color. I see that their Cs (Chinchilla spotting) is the same as our S gene, I will be calling it Cs from here on forth. Now here is the real reason I was emailing you: I noticed that the Fy (fade yellow) is said to be dominant and possibly lethal in the NFRS, but other sites are calling it recessive. Here is the NFRS site: and here is one that says it is dominant: [site gone, 3-22-16]. Finally, here is one that says if it is Fy/-, it is the bronze variety, and if it is fy/fy, it is cold chinchilla— What I’m trying to say is do you happen to know which one is true? We are a little confused. Any insight you can offer would be a great help! Thank you in advance!

AWith the rat genetics, so much is not known because they haven’t had the research testing in the labs like the mice have had so it is a best guess for a lot of these newer colors and varieties. I do know Ann Storey has done the Chinchilla breedings and has been able to fit her theories of her genetics with her real life results. Her article on the N.F.R.S. web site that you list is the one I would go with. Unless a geneticist takes on researching these newer rat colors, we many never know which, if any, is correct. Sorry I can’t be of more help. *

Back to top

March 22, 2016