Comment

Comment by Lynne Cerny on December 14, 2010 at 8:04pm

I can still see the spot but it isn't as light or big as when he was younger!  Sally also has a spot, but she doesn't want anyone to see it!

Comment by Lynne Cerny on December 14, 2010 at 3:02pm

Are you talking about the spot like on Boo's picture?  I've wondered about that also!  This is a younger Boo, I'll have to look at his nose tonite!!

Comment by John Wolff on December 14, 2010 at 1:56pm

I don't buy it, Sam.  I think those little piebald nose spots are some kind of 'birthmark'-type thing.  I'd have to check old photos, but I don't think they change with age. 

The hyper-variable white face and collar markings intrigue me.  If you know how the neural tube invaginates in the early embryo http://en.wikipedia.org/wiki/Neural_tube -- our nervous systems originate with our ectoderm, our skin -- then you can imagine it it dragging along a splotchy patch of differentiated skin along with it, forming the symmetrical or asymmetrical centerline blazes that look so cool -- I guess that this is wht some of these white markings terminate abruptly at the dorsal midline.

 

http://www.cardicommentary.de/Coloursandcoats/White_markings_final2...

The famous Belyaev experiment noted the appearance of white coat markings (check this out!):

http://www.overpill.com/2009/12/21/soviet-scientist-turns-foxes-int...

http://en.wikipedia.org/wiki/Domesticated_silver_fox

But the little piebald nose spots are not congruent with the white patterns, I don't think.  I still think they come from prying open the refrigerator.

Comment by Beth on December 14, 2010 at 12:01pm

I like Sam's scientific explanation and did not know that.  I do know, however, that horses also frequently have pink spots on some of their white markings. 

Comment by Laura Harris on December 14, 2010 at 10:25am

Sam, you're brilliant. Thank you for the explanation! (Also, I was thinking of this picture - is that Vienna on the right?) 

 

I love the other explanations, too. :) 

Comment by Priscilla, CARLY, and Frankie on December 14, 2010 at 10:06am

hahaha those are some cute comments , but SAM your a world of information , arent you! good work!

Comment by Sam Tsang on December 14, 2010 at 9:23am

Hi Laura, if you're refering to this pic, that's Mocha :)

The Pink spot you see depends on an enzyme call "tyrosinase", as a dog ages or situated in a colder climate, some of it's tyrosinase becomes defective - which cannot synthesize the normal amounts of melanin. Thats why you see  Bernese Mountain dogs and Siberian Huskies have seasonal variation in nasal colour.

 

I love Cindi and John's explanation too :)

Comment by Cindi & Twinkie on December 14, 2010 at 6:09am

We just assumed it was Twinkie's beauty mark :)

Comment by John Wolff on December 14, 2010 at 1:30am

It's from prying the refrigerator door open with their snouts at night to steal food while we're asleep. It rubs some of the hair off their nose.  All corgis do this.