A Digression on Dog Genetics, Part 2

eye_chart
Here’s Carlton, really wanting to get out of the doctor’s office. This photo is the best one to show he has pale tan ears.

Yesterday, I shared some information on Carlton the puppy’s “weird eyes.” Today I’d like to document some of the things I learned about how he got to be “the world’s whitest dog.” (And, FYI he weighs 31 pounds now, which makes me think he will probably end up the size of his companions Brody and Harvey, though perhaps less bulky.)

I think that he has a whammo combination of THREE genes that make him pale. I learned a lot, thanks to a great collection of information on dog color genetics by Jess Chappell for a lot of this, along with the doggie eye problem reading I did from the veterinary opthalmomogist’s textbook (see references).

Carlton is not an albino

Nope, he is not an albino. Albinism is not found often in dogs like it is in bunnies, rats, and humans. There are a LOT of genes that can make a dog white, though. I won’t go into detail (you can read it in the links below), but I’ll share some ideas.

Is he a double merle?

At least two veterinarians who have examined Carlton have posited that his coloring is due to being a double merle. What’s that, you ask?

merle
This is a cute little merle dachsund named Maggie, owned by my friend Mandi.

First, merle is a beautiful pattern that occurs in a number of dog breeds (I list some at the end of this article). The base color of the coat is beautifully dappled, and people like it a lot. It will show up if just one parent has the gene (it’s dominant).

Continue reading “A Digression on Dog Genetics, Part 2”

A Digression on Dog Genetics, Part 1

carlton_sit
You can see Carlton’s markings in this photo. The very pale markings around his ears are hard to see, but there.

My lovely puppy, Carlton, is 6.5 months old, as far as we can tell. He weigs 31 pounds, and is all legs and teeth at this point. He loves other dogs, warms up to people, and is generally the best puppy ever. He also has “weird eyes,” as one of our veterinarians put it. She advised that we check with a veterinary opthalmologist as soon as possible.

That visit came on Tuesday, and it’s sent me down a long path of figuring out exactly how Carlton got to be who he is, and why. I wrote up some of this on Facebook, but since then I’ve been doing a lot more research, and as a person who once considered majoring in biology, I found it really fascinating. In fact, writing up my findings is so complex that I am going to break it into more than one post.

Vet visit findings

The regular vet had diagnosed Carlton as having some kind of eye abnormality, in addition to being blue, so she sent me to the veterinary ophthalmologist to see what’s up. This is the same woman, Dr. Yu-Speight, I went to when my corgi, Gwynneth’s eyes went bad (she ended up having them removed and lived 4 more years). We had a wonderful visit.

First of all, Carlton was quite the little man through the whole appointment. He even jumped into the car on command, finally! I am so proud of this dog. He was incredibly well behaved until we got back home, when he went bonkers.

There was a great deal of eye prodding and dropping involved, but they tested everything from tears, to pressure in the eye to the insides. So, he dealt with many substances and implements. I was amazed at his patience, even though he was obviously not enjoying the process.

Sure enough, his eyes are not “normal,” which we knew. But he CAN see, better in darker light, which we also knew.

Continue reading “A Digression on Dog Genetics, Part 1”