Albino Chihuahua Wilbert Visited us in Ceres

All sorts of dogs at

Here’s a picture of Wilbert the Chihuahua along with his human at our Ceres vaccination clinic. Wilbert is a Chihuahua but, of course, what is notable about Wilbert is that he is an albino and what is especially interesting about that is that both of his parents were black colored! In an albino dog, the deficiency in melanin production is the result of a defect in, or the complete absence of, the enzyme tyrosinase which is a part of the melanin production system. The two categories of Albinism are occular – which affects the only the eyes including iris and eyelids, and musculocutaneous which affects the eyes, skin, and hair. In the case of dogs, there is also a complicated relationship to other genes which are responsible for red and black pigment production and the defects of which can produce grey and white coats but not via the tyrosinase-albino path. Albino animals are unusual in their coloration but in every other way are healthy and normal with the exception that the sensitive skin and eyes are more likely to develop melanoma unless protected from the sun. This is possible because the various forms of albinism are due to autosomal recessive genes and it takes one copy of the gene from each parent for the offspring to demonstrate the syndrome. In Wilbert’s case, we know that each of his parents must have carried a dominant gene for color and a recessive gene for albinism. In the pups of their litter, three-quarters of them should have had the probability for having color but one quarter of them should have the possibility of receiving a copy of the recessive gene from each parent. Therefore we can expect Wilbert came from a mostly normal litter. If Wilbert were to ever sire a litter of pups it is a guarantee that his contribution to them will be a recessive gene for albinism but the pups would not have any chance of being albinos unless their mother also carried at least one copy of the recessive gene and the chance of that is very low. Next time we see Wilbert we’ll ask his human what she knows about the color distribution of his siblings. Interesting! – Geoffrey Antipa



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