White-Headed Dog Genetics

[Lawgirl]

Having read some past topics, especially the white-factored dog post, it does appear that white-factor and white-head are two very different things.

 

Does anyone know if the actual genetics behind a white head has ever been worked out?

 

I am asking as I have a B&W BC Oscar who has a white head, with coloured ears. He is in my profile picture, but also below.

 

Here you can see the couple of black tick marks on his head (with my red merle dog).

 

Oscar is definitely not white-factored with no white hairs on his body, and white socks that finish low on his hind legs.

 

Does anyone else have a white-headed dog? Any ideas on the genetic basis for this?

 

For the record, Oscar has normal hearing and sight.

 

Sorry, these are not the best photos, but my better photos are too big to post directly.

[Cass C]

I have very limited understanding of this, but I think white head black and white border collies are just a different type of markings and are not a genetic thing... My split face was the offspring of two traditional marked dogs, so I'm pretty sure it's just the randomized markings.

[GentleLake]

I was under the understanding that white heads is indeed genetic, though through different genes than white factoring. I may be wrong about this, and am always happy to be corrected when my information is mistaken.

 

Cass, if the genes for split face or white heads are recessive, then it could still be genetically determined even if the parents don't exhibit it, just like a red (or other colored [except for merle]) dog can be produced by two black and white parents. Or it could be a more complex genetic variant.

 

I've got a tangential question about white factoring that arose for me in the other thread but I neglected to ask then, but will now since it's come up again.

 

Is it necessary for a dog to have white on the body to be considered white factored? I've had a number of dogs who I've understood to be white factored based on the white on the hind legs, but they haven't had any white (other than traditional Irish spotting) on their hips or backs.

 

Can someone please clarify this for me?

[Gideon's girl]

What I read about white factor was that the dogs display a white streak going up towards their back from a white belly, like a lightning bolt.

 

My split faced dog also has two classically marked parents.

[GentleLake]

Here's the Border Collie Museum's page on white faced/white headed dogs: http://www.bordercolliemuseum.org/BCLooks/SplitFace/SplitFace.html

 

There are a couple dogs on her Patterned White page (http://www.bordercolliemuseum.org/BCLooks/PatWhite/PatWhite.html) that kind of fir the description of what some here have said is white factored. And white factoring is mentioned on the page of black & whites: http://www.bordercolliemuseum.org/BCLooks/BlackWhite/BlackWhite.html

 

Then there's this blog post: http://hillshepherd.blogspot.com/2011/09/white-border-collies.html Don't know the sources.

 

I only ever bred 2 litters. The bitch was a traditionally marked black and white dog who had no white on her hips or back, but did have white running up the inside of her hind legs. Regardless of whether she was bred to a dog with any white running up inside his hind legs, she threw white or white patterned pups. One was an almost completely white pup (he had just 2 small black spots IIRC - he was born before we owned the bitch). Two patterned white pups in the second litter were sired by a dog that wouldn't fit anyone's definition of white factored; his hind feet were white but it stopped well short of his hocks and there was no white on his hips or back. Then there were two almost completely white pups in her last litter, sired by a dog with a lot of white and definitely white above the hocks and inner hind legs but none on his hips or back.

 

Not really sure where I'm going with this other than to say that I'm not sure how simple identifying the genetics of it is.

[Cass C]

I was under the understanding that white heads is indeed genetic, though through different genes than white factoring. I may be wrong about this, and am always happy to be corrected when my information is mistaken.

 

Cass, if the genes for split face or white heads are recessive, then it could still be genetically determined even if the parents don't exhibit it, just like a red (or other colored [except for merle]) dog can be produced by two black and white parents. Or it could be a more complex genetic variant.

 

I've got a tangential question about white factoring that arose for me in the other thread but I neglected to ask then, but will now since it's come up again.

 

Is it necessary for a dog to have white on the body to be considered white factored? I've had a number of dogs who I've understood to be white factored based on the white on the hind legs, but they haven't had any white (other than traditional Irish spotting) on their hips or backs.

 

Can someone please clarify this for me?

Good to know! As I said my knowledge of it was very limited... I'm curious what would happen if for some reason people started breeding border collies with white faces or split faces intentionally... Not encouraging it, but wondering if after a few generations if that would become the norm or would there still be lots of traditional marked border collies in the litters?

[NCStarkey]

Hello everyone,

 

It seems that the quote on the Hill Shepherd website came from this very site (USBCC All About Border Collies). Here's the section about white factored dogs:

 

"There is then at least one allele (maybe two) which causes extreme white spotting, ranging from just a little more than the previous to an all-white body. Greyhounds and pointers also often carry this extreme white gene. This latter, often referred to as "white factor," is a recessive gene, requiring both members of a gene pair to produce the white dog. But it is not entirely recessive; a single white factor will cause variable amounts of white spotting on the dog's body. Usually small spots on the hip or back indicate white factor; some breeders believe that any white extended up the hind leg into the stifle suggests that white factor is present.

Many of the great herding dogs have been white-factored. Notable among them was Gilchrist's Spot; he had white travelling up the front of his hind leg clear to the hip. His grandmother was a white dog named Ann, who was also, through a different line, the great-great-grandmother of Wiston Cap."

 

Regards,

nancy

[GentleLake]

^^ I knew I'd read that before but didn't think I'd ever visited that blog site!

 

Not so nice of the blogger not to acknowledge the source.

[Lawgirl]

Just out of interest, one of Oscar's littermates, who is a traditionally marked tri, recently had a litter with an equally traditionally marked black and white BC. Out of 7 puppies, there are five tris, and at least two split faces or mostly white faces. I think one had a white patch on their back, so is white factored.

 

This is a photo of the litter at 4 weeks old. Just because puppies.