Rat Breeding Articles

Breeding the Chinchilla

© Ann Storey MSc. FIBMS

Origins and early days

The Chinchilla was always one of those varieties that people liked to admire from afar but were not keen to take up for themselves. However, over the last few years other people have been inspired to try their hands at this interesting and challenging variety. There are also myths surrounding this variety which I feel need setting straight.

The origins of the chinchilla

Like a number of other varieties the chinchilla was first found in a pet shop, this time in California in the mid 1980s. The rats were basically agouti berkshires but they showed marked colour paling (that is loss of yellow pigment) up the sides. I suspect they must have been quite pale, or they would not have been taken for anything out of the ordinary. These early rats were taken and worked on by Karla Barber of Emerald Hill Rattery. The strain was more widespread than that because I know that the variety was known to the mid West breeders, especially Alan Gangi, by the mid '90s, and from my early conversations with him he did not obtain them from California. This variety also went by a number of names, indicating that they were quite widespread before the fancy picked them up, probably originating in feeder stock. This following came from Alan Gangi.

"All my chins trace back to AR Hale Bopp of 6h, a bronzed-chinchilla blazed banded who I got in the mid '90s. He was the son of AR Blizzard (a BEW male) and Spatter Paint of AR (odd eyed pearl merle berkie). I had bred from blizzard a few times, and so did Sarah (AR/aristorats), and he had a partial pedigree. I am not sure how much of his ped went back to feeder lines, but there were chins in it. Hale Bopp's mother was Spatter Paint was found by a fancier in a feeder bin in a Florida petshop and sent up to Sarah.

I remember one other rat with the same genes for chin who was bred several times around the same time - Eammon de Valera of RvR- a mink blazed berkie odd eye male who was also found in a petshop (I think it was in Indiana). We never had problems with MC until after Spatter Paint was brought in from what I recall. but perhaps this was coincidence too."

Given the background of these rats, the genes have probably been around a long time. I still recognise the spotting gene's characteristics from time to time in pet shops, although usually without the chinchillation factor.

Other Names

The Chinchilla is also known as Dominant or American Blazed, Aurora and American Husky.

Obtaining the chinchilla

Now importing the chinchilla was not just a case of the NFRS hearing about them and going for it, but the result of a long and proactive search for that variety by John Wells.

The chin, along with the blue, was the 'El Dorado' varieties for John Wells, a prominent fancier of the '80s and early to mid '90s. John was tireless in his search for these two, writing to labs all over the world. I especially remember him telling me that he had found a source of blue rats....in Japan! Luckily for the club's finances the blue rat (later called British blue) turned up somewhat closer to home- in a Croydon pet shop in 1989, which is a story that has been told elsewhere. Once the blues were established (after a fashion), John turned his attention to obtaining the chin. After several false starts, John then found the chins in California, which was excellent as we were on good terms with the Californian fanciers, especially Roxanne Fitzgerald, who really managed the American end of the operation.

As we had not even seen a picture of the rats at this point (no digital email pics then), I was a bit loathe to sign over a large chunk of the club's money (£800) especially when the club had just managed to pull itself out of a large financial hole. However a picture duly arrived of some nice looking chins and we gave the go ahead for the import. We then had a long wait for stock. This surprised me a bit. I wasn't aware then of the very low yield of good chins that you get in any mating. Also I was somewhat alarmed at the high rate of 'bloat' that affected the litters. We were quoted 40% of chin babies.

Eventually we were sent a picture of the four rats we were to be sent. The picture was of four young rats about 6 to 8 weeks old. One was a chin buck with lots of white up the side and a very big blaze on the face (Silverado), one looked like an agouti but we were told he would turn into a chin,(little Paul), one was the velvet buck,( Bailey) and one was a silver fawn which the Americans called Amber and which they insisted wasn't the same as our silver fawns. I wasn't too impressed with the pictures to be honest but it was too late at this point and looking back on it I think we were probably lucky to get one good buck. There should have been three chins but one had respiratory disease and couldn't be sent.

The import went ahead in October 1993 and was quarantined at the Little Acre Quarantine Station, Cambridge, for six months. Roger Branton and I picked the rats up from the quarantine station one beautiful day in April 1994.Bailey, the velvet was going to Joan and Roger by special request. Sadly, due partly to the fact that Bailey's temperament had been permanently soured by the importation, and also because 'velvet' is a threshold trait - little ever came from the import. Velvets are a lovely variety with a short, thick coat like a rex rabbit but the whiskers are straight. There are a few still about. I have seen it in Siamese and I get the occasional one in the chins. However, they are difficult to spot as kittens and don't get a full velvet coat until they are adults. This and the fact that it takes about 4 generations to get velvets out following an outcross to a normal coat means they are a bit of a non starter. Its my understanding that they were originally bred from Russians, who also have a thicker than normal coat.

The amber/silver fawn went to a pet home and I took the two chinchillas. The idea was that I would use them first and then pass them around to anyone who was interested. In the end the only person who was interested was John. Part of the problem was that when I took the rats to the committee meeting at Veronica's the next day, the silver fawn (who had already bitten Roger the day before) and one of the chins (Little Paul), had snuffles. Geoff Izzard then put the mockers on the whole thing by saying that he thought I was very 'brave' to take the risk of introducing a new strain of infection into my rats!

First litters

The two bucks were quite different. Silverado was what I would call a full chin. That is one with no or very little yellow coat pigment (phaeomelanin) left. In addition he had a heavy blaze, an over marked berkie belly, reasonable type, size and temperament (the only one of the imports that didn't bite) and he didn't snuffle. Little Paul however was the opposite, he had a somewhat snipy head, snuffles and was a bit dodgy temperament wise. He would wait behind a box or something and rush out to give you a good bite if your attention was elsewhere. He was also what I would call a half chin, which I have seen variously described as a silver sprig or a cold agouti. That is a low grade berkie belly, no head markings (although they can have them, Little Paul didn't however) and some colour paling up the sides but not on top. He was never bred from, all my chins are directly related to Silverado.

We had a pretty clear idea that was not refuted by the Americans that the chin was the same as it was in other species, that is a mutation on the C (full colour) locus nominally called Cch. Failing that it was assumed that at the very least it was a recessive. Whatever the genetics the idea was to get rid of all the white markings, so that it would resemble the chins we were used to seeing in other species. Roxanne and Linda did say however that they had not seen one without white markings.

I duly mated up Silverado to two nice agouti does who swiftly produced their litters. These contained as expected agoutis and some nicely marked 'Berkshires'. I didn't want those, or so I thought so I passed them on to someone who did. That was Berkie breeder Bernie Rappensberger. I kept back one berkie doe, 3 agouti does and 1 agouti buck. I passed Silverado onto John.

Time rolled on and I couldn't wait to mate up the agouti babies, expecting some chins in the litter. Unbelievably the three does all ate their babies, a quite unheard of event. So back to the agouti buck, three more litters- no £%$* chins!

By this time however the berkie doe I had kept and the buck who had gone to Bernie had turned out to be chinchilla and I realised that something else was going on here. I wrote to Linda Sinclair in the US, who at the time was acknowledged as being the chinchilla expert. Linda said that while she was sure that Chin was Cch she had never actually proved it and that chins always had either white or berkie bellies. She further said that in her experience the best chins were obtained by breeding chin to chinchillated silver fawns,( that is argente crème) and that you never get anything any good out of an agouti outcross.

I got Silverado back from John and mated him up to a silver fawn doe, expecting to get the argente creme out in the second generation and not expecting much except a load of mismarked berkie things in the F1.

Once more I was surprised and got 6 out of 9 chins in the litter, none of which went on to develop bloat (more of this later) To get 6 chins out of 9 is a remarkable and something I have never bettered. There were two bucks in this litter that were very good and went on to be my next stud bucks. The problem at this point was that chin bucks were somewhat unreliable, not nasty as such but you just couldn't trust them. I did show one of these bucks under Peter Fox but it bit him. After this I made a deliberate decision not to part with or show any chins until I was completely sure of them. I am very glad about this, even though it did take some years and I am sure some people thought I was sitting on my hands. This time also gave me the freedom to make sure they were healthy as well. Sometimes you can be in too much of a rush to get them on the bench.

Following on from Linda Sinclair's belief that chins were Cch I mated one to a very nice silver fawn bred albino. If chins had been Cch I would have got all chins, what I got was 75% agoutis and silver fawns and 25% chins, proving that chin could not be Cch.

At this time I was still trying to breed rats with no face markings - a dead end which kept me occupied for far too long! Two Grandsons of the buck who bit Peter Fox were Spotless (because he had no head markings) and Salmo (after the salmon, the colour of which a good chin resembles). Salmo was one of the best bucks I have ever bred and is the chin on the Supreme poster.

Essex mating

About this time there was some controversy concerning the Essex. Some people considered that the two might be related and also there was some interest because it was said that you could breed roans that way. The doe chosen was a choc agouti Essex bred by Jo Pierre/Anne Foster who had lovely type with a super head and ears, length of rump and tail set, all things that chins tend to fail. From this mating came 4 chinchillas, 4 selfs with white feet, 2 berkshires with high white sides, a BEW which died at 10 days and 1 Turpin (chinchillated Essex). One of the chin bucks was Ashlar who went to Lian o'Sullivan.

The biggest chin buck, Hare, was mated to his chin sister Fleet. She produced 4 kittens only in the litter, one of which was a squirrel buck Angel. The other three were all chins. Fleet died when the litter was only 3 weeks old of Corynebacterium kutscheri. I had several more in this line affected by this over the next couple of years. I had not been expecting any squirrels (blue chinchillas) from this mating but had previously started to breed them by crossing a blue agouti doe to Spotless and by this time had managed to produce several, although none of the quality of Angel.

Interestingly there were no Essex . At the time I couldn't get Essex from breeding together 2 chins with Essex parents and I repeated this mating with another Essex.. Nor did I get any Essex from chin x Essex. I did breed Essex when crossing a chin with an Essex parent to an Essex with a roan parent but the yield was low, (3 out of 44 kittens). Another strange thing were the short lived BEW kittens that turned up on 4 occasions in the litters. There was no history of BEW or variegated in any of the lines used for breeding. It is known however in mice that crossing white spotting genes on different loci together can give short lived BEWs. These die because they are severly anaemic. The rat kittens certainly looked it.

Funnily I have used Essex crosses more recently and have got out Essex on the F1 generation. I can only assume that there was some linkage occuring with the earlier matings, that has since resolved itself with a cross over event. Either that or another genetic mechanism, such as imprinting, coming into play. In my experience, in chins the father does seem to have more influence on the markings than the mother.

Some of the rats coming out of this chin x Essex cross have been what is sometimes termed 'broken Essex' or even 'variegated Essex', because they look like a cross between a variegated and an Essex. This is most likely due to the presence of white modifying genes.

I did cross two turpins together. There were 3 Turpins and two PEWs in the litter. I would have expected a mixture of agoutis etc as both Chins and Essex are heterozygous rats. However, this is not what happened. The litter was very small however and I have not had the opportunity to repeat it. The PEWs should have been albinos from the albino cross carried out years before. However, I did get someone to cross one of these PEWs to a siamese (no PEWs were available). The litter was all Essex. which was a shock, to say the least, because if it were true this would mean that the PEWs in the litter were not albinos. Unfortunately I was not able to carry that line on any further. I do still get PEWs out of my chins (one won BIS) and these have been proved by a test mating to be Albinos.

Other marked matings - Chinchilla matings

Mating Chinchilla to chinchilla has always given a mix of full colour rats, half chins and a few chins. The number of chins bred this way is not as high as you would expect.

Chinchilla to half chin gives similar results, but I have bred some of my best chins this way, including Street Spirit and Moon River. In both cases the doe was the half chin.

Half chin to half chin has never given any good coloured chins when I have done the mating.

Chinchilla x Roan

I only did this mating the once and lack the courage to do it again. I used a black Roan buck, Rowangate Frost, to a chin doe. The litter was composed of eight chin babies but all died of megacolon (bloat). I later mated Hare to a roan x essex cross doe and ended up with a mix of berks, Irish, one black chin, an odd eyed, a half chin, two turpins and 2 BEWs who of course died.

Berkshire x chinchilla

This mating was not done by me. From what I understand it produces a lot of berkshire type rats, some very over marked (hi whites) and a cooresponding high level of bloat. It also produces patched rats which are probably chinchillated hoodeds. These patched rats are quite interesting in that they are not hooded at all just have random patches of colour all over the body.

I was given some of these rats back. I did find the level of bloat to be high, also they became infertile very early. It is possible that both these things could be controlled by selection. Certainly bloat can.

Other Chinchilla Imports

Both a patched buck and a chin dumbo were later imported from Holland. As far as I know there are no lines of these rats left now in the fancy as they did throw lots of bloat. Chinchillas do turn up in the pet shop population occasionally but it is not known where they came from.


Chinchilla in the rat has not currently been worked on by any laboratory so anything I tell you here is unofficial but based on my own breeding experience. My results are similar to those that have been obtained by breeders in the US.

The basic chinchilla white spotting, that produces a berkshire type rat with some colour paling on the sides is a lethal dominant. Most American websites give this as S. However, this gene has previously been allocated by the researcher Castle to a silvering gene. Because of this, I have used Cs (chinchilla spotting) which doesn't seem to have been previously used.

For the fading portion I have stuck to the American notation fy. However it has been my experience that this too is dominant although possibly either another dominant lethal or one with incomplete penetrance.(that is, a gene that does not always express itself)

I must point out that the colour fading only works on an agouti background. This is because Fy removes yellow pigment but doesn't affect black. Self chins resemble badgers (where they have a blaze) or berkshires (where they don't). Black chins closely resemble black Essex and can only really be told apart by test mating

CsCsFYFY, CsCsFyfy - lethal, foetus absorbed or possibly born as BEWs which die very young.
CscsFyFy - maybe lethal or may be show chinchilla
CscsFyfy - Show chinchilla
Cscsfyfy - half chins
cscsfyfy - full colour

Just to confuse you all the situation is somewhat different for squirrels (blue agouti chinchilla) and argente cremes (silver fawn chinchilla).

For squirrels the yellow pigment is much less in the beginning, because the blue gene mutes yellow pigment. This means that squirrels can be either half blue agouti chins (Cscsfyfy) or full blue agouti chins (CscsFyfy).

For argente cremes, in order to get the apricot flush they are half chins. Full chin argente cremes resemble pale coloured champagnes with a white belly.

One further recognised Chinchilla variety exists, although you rarely see it and that is a Turpin. Turpins are probably Chinchillated Essex and I will be discussing them more later.

A gene that sounds very similar to chinchilla spotting (Cs) in the rat has been described in the scientific literature for mice. I must point out that the interest in this gene in the mouse is due to the fact that it is the gene responsible for aganglionic megacolon in the mouse, and is present in humans as one of the genes responsible for Hirschsprung's disease (Waardenburg Syndrome type 4 WS4), which can also shows up as a blaze on the front of the hair. This allele is called SOX10Dom and like Cs is a lethal dominant. The SOX10 gene is essential for the development of the neural crest and is present in a very wide range of organisms, not just vertebrates or indeed animals. The amount of white spotting on the mice was found to depend on a modifier locus (C3H) on Chromosome 10, which is also a modifier of other white spotting genes in the mouse. This modifier is described as being a recessive with 50% penetrance (This means that only 50% of mice with two copies of this gene will show white spotting) Interestingly the amount of white was not related to the presence of megacolon. This is due to another modifier B6, in the mice in this experiment.

If this gene SOX10Dom, is similar to Cs, then it would explain many things. Including, the reason why both myself and Alan Gangi were able to breed away from megacolon so quickly (because the stock we bred them to was free of the megacolon modifier) and would explain the variation and unpredictablity in white spotting that occurs when they are bred to various other rats with other white spotting genes. If this model is correct this could be because the other pattern modifiers in those varieties are all having different effects.

Varieties - Chinchilla Standard

Top colour grey, caused by the intermingling of black guard hairs over a pearl white ground. the whole to give a sparkling appearence. Undercolour dark slate blue, intermediate portion pearl, tips black. All the underside to be white with a clear demarcation between top colour and belly. Head markings to be present or absent. Where present either a blaze or a spot to be acceptable. The standard for both is as follows:

Headspot; Headspot to be centrally placed on the rat's forehead and no bigger than the rat's eye.
Blaze; This is to be a wedge shaped symmetrical blaze of white starting at the nose and extending up the face to the forehead. The blaze to cover the whisker bed and to taper to a fine point midway between the eyes and the ears. Markings not to extend onto the cheeks or the eyes.
Forelegs to be white to half their length, back feet white to the ankle (hock or tarsal bone). Tails to be pied.
Faults; drags, yellow or brown tinge to the top colour, skewed or mishapen blaze, uneven or overlarge headspot.
Top colour...........................20
Head markings......................5
General conformation..........50

Chinchillas are very difficult to get right in the first place and like all marked, produce only low numbers of showable offspring. However good ones have a very long show life, certainly into their second year. Bucks are usually better coloured than does as the black ticking is darker in tone and they are less likely to carry excess red pigment. This may be because bucks carry less red pigment than does in the first place. A show chinchilla is a chinchillated agouti. The top colour should be a sparkling mix of black and pearl white. The effect of the chinchilla coat has been likened to moon on the water but a good one always reminds me of the skin of a salmon. The belly and all the underside should be white, with a clear demarcation between top colour and belly. Face markings are often the downfall of the chin and these must conform to the standard. Practically the head spotted type is the easiest to breed.

Size wise chins are usually of good size. Type is quite variable and there is a tendency if you breed chin to chin for them to get cobbier and for the eyes to get smaller. Does are usually better for type than bucks. Some half chin does, usually ones without any facial markings with the possible exception of a white lip, are quite narrow and whippetty looking. Normally I would not recommend the use of rats like this in any breeding programme. However, I have bred some of my best chins out of rats like these when they have been crossed with a good coloured buck with good facial markings

Eye colour is not mentioned in the standard and can be interesting. Basically it should be black but, due to the white facial markings affecting the iris, chins tend to have a condition called aniscoria, which is where the pigment in the iris is reduced and the pupil is bigger than normal. For this reason chins often appear to have the glowing red eyes of literature when viewed with a torch at night.

Ideally to start with I would recommend one good coloured chin buck and a couple of pale coloured argente creme does. However you are not likely to get this so I would settle for a trio of the lightest rats you can get. Mate your chins together when they are about 4 months old.

Chin litters are usually a bit smaller than normal due to the effect of the lethal genes and there used to be problems with infertility. However I wouldn't say there were any particular problems with it now.

Litters are usually composed of some agoutis, some berkshire type rats (half chins), possibly some cinnamon chins which are not standardised, silver fawns, argente cremes and hopefully a show chin or two. However it is difficult to spot the show chins until they get to about three weeks old. They start out looking like the half chins but the agouti coat has a slightly blue grey appearence and the belly starts to 'bleach out' that is the whole belly apart from the white markings starts to lighten. As the hairs on the tail start to come through they take on a 'pepper and salt' appearance.

Half chins look like ordinary berkshires. Either half or full chins can have white face markings although they tend to be bigger on full chins. However all will have a white lip and a white tail tip, unlike Hh Berkshires.

Colour is slow to develop. As I have said, they look like bluish coloured agouti berks to start with but the edges of the markings are blurred in a real chin and not clear cut as in the half chin or berkshire. Also the same brindling is not present on the half chin tail.

At about 8 weeks, as the second moult starts to come through, the yellow pigment starts to be removed and the coat becomes paler. A brownish tinge usually remains along the back and down onto the rump. This may take some months to clear. The better the chin, the quicker it will go.The black ticking should remain clear and sharp. Half chins will show some paling up the sides but the top colour always remains a dull agouti shade. By eight weeks the belly should be all white on a show chin. Some chins clear the yellow pigment well enough to be shown as kittens. Chins are shown in the marked section of the show.

Apart from the show chins the ones to keep from the litter are the argente cremes and the half chin does. Keep any rat who is a show chin, even if the face markings are poor. I have bred plenty of well marked rats out of ones with 'the boy who lived' or slash blazes to be of the opinion that the shape of the blaze is not of prime importance in breeding stock - colour however is and the true chin colour is an elusive beast. Obviously though if you breed any with good face markings these should also be kept. The inheritance of facial markings is not clear cut, but they may be due to a recessive modifier with incomplete penetrance, if it follows the mouse model described above.

Sometimes hi white kittens are born, especially if either of the parents is a marked rat. A hi white is a rat where the white pattern comes well up the sides and the face markings are very pronounced. These kittens may be full or half chin but either way are the most likely rats in the litter to suffer from bloat or megacolon as some people prefer to call it.

A bit about megacolon

This condition is caused by a lack of nerve endings in a portion of the colon or occasionally the ilium. To give the technical terminology, its recognised by agangliosis of the distal gastrointestinal tract. The reason for this is believed to be as follows:

The embryo develops from being a blob of cells into a ball with cells around the outside and a hollow centre. As the cells divide and multiply, the cells fold inwards along the back. The nerves and pigment cells originate from the same group of cells in this fold, which later becomes the spine. The name of this fold is the neural crest. These ancestor cells start to migrate out from the neural crest through the embryonic skin surfaces, both interior and exterior. At some point pigment cells and neurones differentiate. The gene responsible for slowing pigment cells in hooded for example does not affect the neurones so obviously kicks in after this separation. The gene responsible for chin spotting, like some other white spotting genes in other animals, presumably kicks in before, or in my opinion about the same time as, this separation. This means that along with pigment cells not getting through to all areas, neither do the neurones. Bloat in rats is clinically analogous to 'Hirschprung's disease' in humans and has a similar clinical picture to grass sickness in horses and mucoid enteropathy in rabbits. Both these last two are believed to be caused by bacterial toxins killing off the neurones and are linked to problems in the diet.

In any of these conditions, due to the absence of neurones in a portion of the gut, the gut is unable to function properly. While the kitten is on milk this is not such a problem but once they start to take solids at two weeks or so the gut is unable to pass the solids past the patch of damaged gut. This leads to a build up of solids upstream from the blockage. The gut becomes very distended (megacolon), the kitten loses weight and the belly bloats. Occasionally some watery diarrhoea may be present due to the body trying to liquefy the blockage. Kittens with this condition can survive some weeks but it is invariably fatal. Occasionally adults may get secondary megacolon, although I have only ever seen this once and it can follow on from abdomenal surgery. This is much slower in onset.

The rats my chins came from had a high incidence of bloat (approx 40%). Whether this was 40% of the whole litter or of the chins I don't know. However I have never had this incidence or anything like it. The incidence started around 10% swiftly dropping to 1 or 2% after a couple of years. After this I only had increases when attempting certain experimental matings. I haven't had a bloaty kitten for about four years now.

Alan Gangi reckoned that the incidence diminished with inbreeding and I would agree with that. However, both I and others have outcrossed chins recently and again there have been no bloaty kittens. However, there is always a possibility that it could come back so all chin breeders must be on their guard.

The possible genetics of this is discussed above under genetics.

Developing your strain

As you are breeding your chins it is important to always include one good coloured chin or one pale argente in each pairing. Pair the good chin to an argente creme (either colour) and the pale argente creme to a full or half chin.

If you have no argente cremes use a silver fawn or an Essex to a good chin. The use of an Essex increases the likelihood of a hi white baby or rats with variegated type markings but I haven't had any bloat out of this mating for a while.

Do not use agoutis unless you are in dire straits and have nothing else. It takes several generations to get the colour back after this mating. Having said this, if you are losing type, then you should consider it.You need to keep a close eye on type, especially any tendency for the eyes to get small which seems to be a problem in this variety.

If you get rats with good face markings and you should, mate them back in. Also as I have previously mentioned, if you get any whippet type does with the muddy top colour, try mating them to a good buck. You may be very surprised at the result.

Other Varieties - Argente Creme

Standard: The back of the rat to be a delicate shade of apricot, ticked with silver and shading to a cream on sides and face. Head markings not to be present. Undercoat white, belly white, eyed red.
Top colour............................15
Side Colour..........................10
General conformation...........50

The argente creame is a chinchillated silver fawn (or washed out silver fawn as one judge recently called them) and like all chins comes in two forms - full and half. Full argente cremes are creamy in colour and resemble light champagnes. For this reason the half chin is the standard colour. This has a flush of apricot (pale orange) along the back and fading down the flanks. The points (legs nose etc) to be pale cream and the underside to be white. The points should fade smoothly into the body colour. As this rat is a silver fawn; even, silver ticking should also be present.

Like all chins they have more yellow pigment as babies. This means rats who are a bit too orange as babies will probably be the right colour as adults and kittens who are the right colour as babies will correspondingly be too light as adults.

To show argente cremes need to be in good coat. Any trace of moult will spoil the shading. They need a steady development as kittens without any check, which will affect the coat quality.

Argente cremes are the easiest of the chin group rats to breed and if you want to breed them you should be able to get reasonably good rats to start you off, as there are a fair number about now.

Argente creme, either half or full, to a typy silver fawn is the best pairing. You can get a reasonably good idea of the kittens to keep at 14 days. Light ones (full) can be used for chin breeding; medium ones, showing some shading, are the ones to keep for exhibition and any silver fawns in the litter can also be shown successfully. Out of the shaded kittens the paler ones will show better as kittens, the darker as adults. Judges also have their preferences over light or dark so until you know what these preferences are you would be wise to show one of each.

Since the numbers of showable kittens is relatively high you have every opportunity to select for type. This means you can also have a supply of typy rats to mate into any chins, who could usually do with it!

Unlike the other chins Argente cremes are not shown in the marked section but in AOV. This is because unlike the other chins it is perfectly possible to breed off any facial markings, due to the half, and not the full, chin being shown.

Other Varieties - Squirrel

Standard: Top colour silver blue, caused by the intermingling of blue guard hairs over a pearl white ground. Undercolour slate blue, intermediate portion pearl, tips blue. Underside to be white with a clear demarcation between top colour and belly. Head markings may be present or absent. Where present, either a blaze or a head spot to be acceptable. Blazes to conform to the std for a blaze, head spots to be centrally placed and not to be larger than the rat's eye. Forelegs to be white to half their length, back feet to the ankle (hock) Tails are pied.
Faults: Drags, yellow or brown tinge to the top colour, skewed or mishapen blazes, misplaced or over large head spots.
Top colour/ticking........................................20
Head markings...........................................5

A squirrel is a chinchillated blue agouti and is a stunning variety. On the face of it they should be easier than chinchillas because blue agoutis naturally have less visible yellow pigment than agoutis. (Actually the amount of pigment is about the same, just that the shape and positioning of the pigment granules is different in all blue rats) This means that both the half and full chin version can be shown, although the full chins tend to have better markings. Chinchilla does not affect the blue pigment.

Traditionally British blue was used and some of the problems that occasionally beset these did make breeding squirrels more difficult than it should have been. Consequently they were prone to fertility problems, Corynebacterium kutscheri infection and spots, although the much vaunted haemorrhaging did not occur.

However British blues are generally much healthier now and the current rats seem to be healthy enough.. Alternatively there is nothing to say Russian blue agouti couldn't be used instead.

To make Squirrels , pick a Russian or British blue agouti doe who is quite dark blue in colour without much in the way of yellow pigmentation. Cross to a good coloured chin. From this you should get the normal selection of chins, half chins, agoutis etc but no squirrels unless your chin happens to be carrying blue. Select out from the babies the best chins. You can either mate these together or to the blue agouti parent. Either way you should get some squirrels in the litters.

They are born looking like blue agouti berkshires but as with chinchillas the yellow pigment will moult out.

You need to select for good blue ticking and no yellow pigment, alongside the correct pattern. Remember that the belly becomes whiter as the kitten develops.

Squirrels are classified as marked rats but are currently shown in Guide Standard.


New Variety Standard: Marked rat with colour combined to defined areas of the face and a wide band of colour sprinkled in a wide band down the back. Face (similar to the roan) - two triangles of colour from the ears to points at the eyes. Triangles to meet between the ears. This colour and the colour along the back to be mixed with white to give the appearance of the colour being lightly sprinkled onto the white background. The colour on the back to be present in a wide band.

The Turpin is a rather enigmatic variety, originally developed by Shiela Sowter and Peter Mitchell and named after the famous highwayman because of the facial markings, which are meant to look like a mask.

Only a relatively small number have ever been bred and even fewer have ever been bred from. Speculatively they have been called chinchillated Essex or Cscs Fyfy (or FyFy)HroH. My only problem with this this that on the one occasion I did mate two Turpins together the resulting litter of five contained 2 PEW (the line carried it) and three Turpins. You would have expected a mixture. Still, it was only one litter of five.

When originally bred they had a reputation for being 'difficult' and dying young. True, mice with multiple marking mutations have a tendency to be anaemic and these rats certainly could be a bit pale around the ears. However, the later few that I bred were quite a bit fitter and lived to about two.

They are quite attractive rats in some ways but the standard is very difficult to achieve, especially in a variety where so few are bred. The markings are similar to a striped roan except that the blaze and the face marking start higher up. The two facial triangles starting from the ears, apex at the eyes and meeting between the ears. I have never seen a Turpin with the correct facial markings, saddle and colour sprinkling. Most I have seen had either no face markings at all or were devoid of colour on the neck or shoulders.

Stock is not available in this variety as far as I am aware so if you want to breed them you will have to make your own. They can be bred using a straight chin x Essex cross, although you will be lucky to get more than one (if any) out of the litter. If you don't, cross the chins to any Essex born in this litter together and hopefully you may get some out the second time. The most reliable mating I found was by using a chin x Essex buck with an Essex x roan doe. As I said, this is not an easy variety. Any one who wanted to have a go with them would be advised to speak to Sheila to get a few more tips.

Turpins are shown in New varieties but none have been seen on the show bench for many years.

Interestingly, but not surprisingly a number of different splodgy marked rats can be bred out of chins crossed with other marked rats. This can also happen when crossing Essex to marked as well. The presence of a face blaze on one parent also seems to increase the amount of white spotting in the litter. This is almost certainly due to the effect of different pattern modifiers. In the US both chins and variegated are known to produce rats with 'collars' a marking that does not occur in the UK.

Unstandardised chinchilla varieties

These rats have NO standard so before they were shown in New Varieties you would need to write one and have it agreed both by the standards officer and the rest of the committee.

Cinnamon chinchilla: Cinnamon chinchillas are chinchillated cinnamons and look like chinchillas with mid brown, as opposed to black, ticking. They quite commonly appear in chinchilla litters because most agoutis carry cinnamon. They have never been given a standard, not least because I have never pursued it. They are not unattractive however and don't resemble any other variety, so there is no reason why they couldn't be shown if anyone was interested enough in this project. Foundation rats should be easily enough obtained from any chin breeder.

As As with any other chin, you would need to breed out the yellow pigment. This is a bit easier with cinn chins as cinns have less visible yellow pigment in the first place.

Lilac Agouti Chinchilla (pastel lynx): As you would expect, the black tickling is replaced by lilac. I have only bred one of these and he was infertile. however the colour is really striking and I do intend to pursue these. There are two ways of breeding these, either squirrel to lilac agouti or cinnamon chinchilla to lilac agouti. In the case of the squirrel cross you may get lilac chinchillas out first time, as many blues are carrying the genes necessary to form lilac. If you don't, mate any squirrels or cinnamon chins etc in the litter together. In the case of the cinnamon chin cross, this is more unlikely as most cinnamons do not carry blue. However, mating together any of the cinnamon chins in the litter should throw lilac chinchillas. You do need to make sure that any lilac agoutis you pick for tis process are from a good strong line that is not prone to respiratory disease or reproductive problems as these can be issues with lilac agoutis.

Other possible colours

No Russian Chinchillas have been bred to date and the mix of the two varieties could be very interesting. A Russian dove agouti chin would have pale grey ticking over pearl and a Russian silver ag chin would be even more beautiful with pale blue ticking over pearl. The Russian dove agouti chin could be bred relatively easily by crossing a chin with a Russian, then crossing the F1s together. This is likely to be a longer and more problematic process with the Russian silver agouti as you are dealing with at least one extra recessive, plus at some point you would get both Russian and British squirrels in the litters. I am not sure how easy these would be to tell apart, but you would need to, as in order to get out Russian silver agouti chins you would need to breed them together. A slower, but possibly better way would be to breed separate lines of Russian squirrels and British squirrels, then to cross these when you were happy with them.

However, in case you thought that this was a licence for you all to leap on these possibilities with a happy cry - stop. This is not a race, no one will thank you for being first on the show bench with X, Y or Z if it is unhealthy or eats judges for breakfast.

First, as with all breeding you should ensure your foundation stock is fit and of good temperament, then proceed carefully, like the tortoise, not the hare!


I hope this series has given you something to think about but if you take away nothing else I would like you to bear the following in mind.

  1. New varieties have problems
  2. These problems can be overcome if you work hard, use your brains and don't give up.
  3. Rome wasn't built in a day. Don't expect to get where you want to be in a year or two. Five to eight is usual.
  4. Don't rehome the offspring to unsuspecting owners until you are as sure as you can be of the health and temperament.
  5. For the non breeders of any variety, don't go round spreading rumours of varieties you have never bred and of whom you have no personal experience. Hearsay is of no value in any walk of life. Get the facts from the horse's mouth first.


I would like to dedicate this to Linda Sinclair, the American Rat breeder who gave me so much useful advice when I was first breeding chinchillas. Linda died tragically a few years ago at the early age of 49. She is much missed by all her friends.