AFRMA

American Fancy Rat & Mouse Association

This article is from the WSSF 2008 AFRMA Rat & Mouse Tales news-magazine.

The Cinnamon Pearl Rat

By Ann Storey, N.F.R.S., England

From Pro-Rat-a, No. 156, Nov./Dec. 2006, the N.F.R.S. journal. Permission given to reprint article.


STANDARD Coat to consist of three bands of colour from the base up – cream, blue, and orange with silver guard hairs; to give an overall golden appearance with a silver sheen. Belly fur pale silver grey. Foot colour to match top. Eyes black.

  • Points
  • Top colour
    15
  • Ticking
    10
  • Feet
    10
  • Belly
    10
  • Base coat, cream
    5
  • General conformation
    50

History

The Cinnamon Pearl is a modern breed of rat, and there is no evidence that it existed prior to the modern fancy, although its ancestors the Mink and the Cinnamon, probably did. It is just possible that Minks were shown in the Edwardian era but they may have been exhibited as Blues or Chocolates. At least one rat that won best in show as ‘one of the best blues ever shown’ later moulted out into a good chocolate! Anyone who has ever kept Minks will recognise this chameleon-like behaviour, although I have occasionally seen this effect in Blues. Cinnamons were also in existence by 1935 when they made it into the National Mouse Club standards, but then they were called Fawn Agoutis. Before this in 1921, there is a mention of a new variety in Fur & Feather in an article by Ralph Blake that sounds very much like a Cinnamon. There is another article in Fur & Feather in 1932 which mentions smokes. These were owned by a Thomas Adams and from their description were probably Minks.

The founders of the Cinnamon Pearl, the Pearl, and the Mink were Clive Love and his daughter Sue of Genesis stud. Somewhere back in the early days of the fancy, they had obtained some Minks. At the time there was no standard for Minks and the fancy was largely ignorant of them; however, they were available in pet shops. (I owned one bought from a school in 1973.) Some of the rats owned by Genesis stud had a light base coat and when these were mated together a pale coloured rat resulted. These were the first Pearls. Clive exhibited these at the London ’76 in unstandardised and very impressive they were too, although we would consider them to be very dark Pearls now. The results of further breedings with Cinnamon, was the Cinnamon Pearl. The Cinnamon Pearl was standardised in 1979 by Clive and Sue Love although Jackie Chapman also bred them. However, for reasons that are not entirely clear, the variety nearly died out after this. The reasons behind this were probably first due to the rats’ genetics and secondly the fact that the early Cinnamon Pearls were big and fit when the Loves had them but seemed rather fragile in other people’s hands.

The saviour of the breed was a large, maloccluded buck called Jasper whom Sara Handley had acquired from Sue. There had been no plans to breed from him due to his teeth and it was only with much persuasion that Sara mated him to a typy Cinnamon Hooded doe. Other matings occurred, but nearly all the current Cinnamon Pearls and Pearls have come down from one of the bucks from this litter called Repsaj; all the other lines having died out. Maloccluded kittens still occurred for some years but I am not aware of any for a while. Due to the shortage of suitable does, Repsaj, at the time owned by Tony Jones, was mated to some Siamese does that originated from Roy Robinson’s stock. While other Cinnamon Pearl lines were available at the time, one by one they all died out. No doubt some would criticise the use of a maloccluded rat but without this, the Pearl and the Cinnamon Pearl most probably would not exist now.

Genetics

The Cinnamon Pearl is formed by the interaction of two genes, the recessive allele m (mink) and the dominant Pe (Pearl). Its genetic formula is AAmmPepe or AammPepe.

Pearl is a lethal gene. This means that when it is present as a homozygote (PePe), the rat dies before or shortly after birth and therefore all Pearls and Cinnamon Pearls are heterozygotes and as such do not breed true. They also have smaller litters on average when mated together. The pearl gene and the agouti gene are both on the same chromosome, meaning that they are linked. The practical problems with this are that if you mate a Pearl to a Cinnamon Pearl, you should not expect to get many Cinnamon Pearls out. In fact, it is possible that all you will get are Cinnamons and Pearls. This is because Agouti is being inherited with pe (non Pearl) and non agouti with Pearl.

In Cinnamon Pearls, most of the brown-grey pigment present in the Cinnamons (base coat and guard hairs) is converted to creamy white. The exceptions are a small band of blue between the white base and fawn top colour and a small blue tip on each silver guard hair. The smaller amount present on the tips, however, the better as too much will give the animal a sooty appearance, especially on the face. The aim is a clear old gold colour caused by the intermingling of the three colours. This colour does not occur on genuine babies, however. These are a silver buff colour. Golden coloured kittens are probably over age, a common exhibitors’ trick in breeds where the depth of red pigment is important. Conversely, some adults are starting to lose the fire in their top colour and appear too light. This is also a fault and should be guarded against. Colour can be improved either by selection within the strain or in extreme cases by outcrossing to a very good coloured Cinnamon. The belly fur should be a pale grey with no white patches. Unfortunately, the rats with white patches (usually on the chest) are less prone to sooty top colour and the use of a few in the breeding pen is unavoidable. It is possible that Cinnamon Pearls sometimes carry the Irish white spotting allele hi. Occasionally, Pearl and Cinnamon Pearl rats are born with streaks or patches of Mink and Cinnamon fur respectively. These patches seem to follow the route of the peripheral nerves and are probably due to reversion mutations in the early pigment cells as they migrate in the embryo. In California, these rats have been selected for and improved. They are shown as Merles.

Breeding

Cinnamon Pearls are very popular with novices, which is unfortunate as they can be difficult to breed. This difficulty is in part due to maintaining type and colour while coping with the fact that the gene is both linked and lethal. Good type and size are essential in a Cinnamon Pearl; small rats or rats with small eyes just do not win. A good rat must have big black eyes set in a broad skull because the eyes are a major part of the breed’s attractiveness. Years ago there was a problem with narrow skulls and slitty eyes, but you don’t see these now. However, things can soon slide back if you aren’t careful! Large well-placed ears help to frame the eyes and balance the wide skull. These are covered with fine grey hairs. There is a tendency for the heads to become short. This must be selected against.

The body tends to be short and cobby. Apart from selection for longer individuals, correct husbandry can help this and if you do breed any long-bodied does, you should keep hold of them. Because of the lethal gene, litters tend to be smaller than those of other breeds. Cinnamons usually turn up in Cinnamon Pearl litters. They are not much good for breeding or showing as Cinnamons as they usually fail colour and are often silvered. They are usually bigger than the Cinnamon Pearls in the same litter. Some breeders have used these Cinnamons to cross into Agoutis in order to improve eye in Agoutis. They will do this but they do not do much for the colour, and I can’t recommend it. Some Cinnamon Pearl breeders in the past who have had obstetric and infertility problems with Cinnamon Pearl does, like to use Cinnamons instead. However, this tends to increase sootiness in the offspring.

These supposed infertility and obstetric problems (usually uterine inertia) deserve comment. As good Cinnamon Pearl does for showing are not that common, there is a tendency for breeders to show does for a long time. When they eventually get round to breeding from them, they are usually old (nine months and over), fat (Cinnamon Pearls are prone to get fat), and it is the wrong time of year. Many people like to breed their show does after London [Sept.] or Bradford [Jan.], understandably to see if they can win a big one; however, it has to be said that rats just do not breed well during the short daylight hours. If you can get them pregnant at all, the litters are often small and the risk of inertia is higher in my experience. This, coupled with age and fatness, are a recipe for disaster. Cinnamon Pearl does tend not to be such good milkers as Agoutis and Silver Fawns, but I think that this could be improved by selective breeding. Does that have had good-sized first litters and have reared a nest of nice plump kittens, should be used again and their daughters considered as potential breeding stock in addition to their other points. Does that have reared only a poor first litter, however, should not be used again even if they look great. After weaning, provide plenty of space and good feeding. Do not let them become at all overcrowded because this variety will not grow properly if this happens.

Cinnamon Pearls have good long show lives once their colour comes through and both bucks and does show well. Bucks can be shown until their coats become spiky and does up to a year if you are not going to breed from them. If you do decide to breed from them, do it young, and then most can be shown again about 8 weeks later.

If you select for bucks with a short coat, you will be able to show them for longer. Little show preparation is necessary except for ears and tails, but keep the bedding clean so that the bellies do not become stained.

There are a few health conditions that are inherent in Cinnamon Pearls. The best known one is malocclusion. This is getting rarer but still occurs. It shows up at about five to six weeks old as a swollen top lip or whisker bed. Examination of the teeth will show misalignment of the incisors. This can be controlled by clipping every ten days or by surgical removal of the incisors. The rats should not be bred from. Another condition is obesity which the does especially are prone to. This is proven to lead to a much higher incidence of mammary tumours and infertility so be careful not to overfeed your adult does. There are reports of other conditions, including Cushing’s disease and diabetes, so it is possible that this is a variety with some physiological abnormalities. Therefore, it is important to breed from fit stock only.

This is a variety very suitable for a small specialist stud or the breeder with a few rats who is essentially a pet owner first. The litters are small and the surplus easy to sell as pets and the rats have a long show life. However, care must be taken not to overfeed. There have been a number of very successful breeders of this variety over the years including Sara Handley, Tony Jones [Kingsley], Nicky Jones (no relation!) [Holywood], and Sue and Paul Threapleton [Serendipity]. *

English Cinnamon Pearl Rat
An English Cinnamon Pearl doe owned and bred by Mayumi Anderson, Bii Rattery.

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Updated March 1, 2014