Here's an explanation about eye shine and how it relates to the type of coat. It is thought that a green eye shine indicates a silky coat, and this is related to the "tapetum", that causes the metallic like shine of the yorkie coat. Their hair is not black/black when it's silky, it's more of a metallic/black that can range from grayish silver to charcoal black, but if their coat will be silky, they often have green eye shine. This green eye shine is eliminated if the picture is taken in daylight or if additional lighting is used, it's only happens if you use a flash. Your baby will probably have a beautiful silky coat.
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The eye in all animals except pigs and man have a reflective layer along the back of the retina called the tapetum. This layer serves to reflect light to allow maximal usage of the available light. In some animals the tapetum is colored in others it is not.
The reddish color that you see in human eyes is the reflection of the blood vessels in the back of the eye because the tapetum is NOT colored. This is the same in the "red eye" of the Yorkie.
The blue and green you see in the Yorkie's are from a pigmentation in the tapetum -- how this relates to coats I am not sure.....but could be that pigmentation of the eye and coat texture are related genetically. Tapetums are very beautiful -- metallic, brilliant colors in most animals.
You can watch Yorkies, clipped down or in full coat, outside in the sunshine ... and you can easily separate them into two groups - those with a "blue cast" to the coat, and those with a "gold cast" to the coat.
Those with gold or bronze cast to the coat have eyes that reflect a flash bulb or flashlight with the "red eye" or "shiny" red reflection to the pupil.......no pigment.
Those blue cast dogs always seem to reflect blue or green from the pupil.....pigment.
The "red eye" dog has a thicker, softer, more opaque (not shiny silky) coat ... silky coated pups look kind of straggly.
What is going on is that those with the gold/bronze cast has LESS eumelanin (black) and more phaomelanin (yellow). Typically phaomelanin (yellow) does NOT get put in the tapetum. So NO tapetal pigment results in red color from the blood vessels. Whereas the blue cast dogs have more eumelanin resulting in a pigmented tapetum and the reflection that you see is bluish or green. It's very similar in chocolate and black Labs-- chocolate labs tend to have pale gold or red tapetums while the black labs have brilliant green and blue tapetums.
Again it has to do with overall production of melanin (pigment) and where it is put. It also has to do with whether the dog carries the genes for true blue, clerical blue or black AND whether they also carry the gene for progressive graying (dilute). That is my explanation I have learned from study of the breed and genes and pigment.
Is it any wonder that Yorkies are difficult to breed to the standard......Eye Shine |