Tail question (pre-caudal / violet gland)

[Gaby]

But this time not about the shape, but the colour.

How is the black marking in the middle of the tail called? I mean the little black "cigar band" in the shape of a "V", if you know what I mean. Mila has a lot of black hairs in her coat and you can see it very good with her, for example on this picture (you can see it now much better then on this picture that was made almost two weeks ago):



Is this something that all Tamaskan have? Or shouldn't have? And has it some kind of function?

[Mylingen]

That is where the tail gland is.

"The tail gland of canids is a hepatoid glandular organ surrounded and penetrated by powerful hair erector muscles squeezing out its lipoprotein secretion onto the skin surface. The gland is most developed in solitary species (Arctic, red, and corsac foxes) where it is represented by powerful glandular layer with large secretion containers—cisterns. It is less developed in the jackal; there are cisterns but glandular lobes do not merge into a layer. In the raccoon dog, wolf, and domestic dog the gland is composed of small lobes without cisterns. Hepatoid glands of the tail gland are represented by two histological variants distinguished by the presence or absence of hydrophobic lipids in the secretory cells. The excretory ducts are formed by lipid transformation of the cellular bands."
http://www.springerlink.com/content/q630k3wm83417k12/

It is also called the violet gland btw.

[Sylvaen]

Is this something that all Tamaskan have? Or shouldn't have? And has it some kind of function?

Yes. All dogs have that, it marks the location of the "pre-caudal gland" (aka 'violet' gland)
In wolves, it is an active scent gland but, in modern dogs, it only functions in some breeds (such as Rhodesian Ridgebacks).
However, the location of the inactive gland can still be seen in almost all dogs (just sometimes it is the same color as the coat so isn't very noticeable).
With Tamaskans and other arctic breeds the black spot is quite obvious as a puppy but by adulthood it blends in with the dark guard-hairs all over the tail.

Wolves have a working pre-caudal gland. It is a scent gland located at the base of the tail. Some northern breed dogs have a remnant of it, but it is a different colored spot or patch on their tail and not actually the gland itself.
http://wolfdog.ws/html/differences.html

[Gaby]

Thanks for the explenation!

So in the dog it is a remaining trait that they cannot use anymore if I understand it correctly. I like it, it looks kinda cute.

I wonder how it will blend in with Mila, she is going to be very dark before it can blend in, she already has a almost totally black stripe/saddle on her back.

[Sylvaen]

So in the dog it is a remaining trait that they cannot use anymore if I understand it correctly. I like it, it looks kinda cute.

Correct. Though it is still functioning in some breeds, in most dogs it is just an inactive gland and in some breeds it can't be easily located at all (such as in labs, etc because it is the same color as the coat, sometimes you can see that the hairs form a pattern in that location but the color is the same as the rest of the tail). In northern / arctic breeds it is fairly easy to spot though, because it is normally a much darker color, especially on young pups.

I wonder how it will blend in with Mila, she is going to be very dark before it can blend in, she already has a almost totally black stripe/saddle on her back.

Well, the dorsal stripe / saddle will continue down the length of her tail, and she will get darker guard-hairs (with black tips) so that her coat will have a peppery appearance (the agouti gene creates bands or stripes along each hair) so when she is older that particular spot won't be so obvious. Jasper had the same as a pup, I'll try to find some old pics so you can see the difference.

[Nino]

Here you can see the V thingy on Sølve

at 13 weeks old


at 5½ months old

[WhiteElkStag]

I grabbed a couple of pictures of Rhea as she grew her coat. Sophie was generally darker throughout so we couldn't see the development quite as clearly.

[TerriHolt]

i'm impressed with how u got the shot of the 1st pic to prove your point...

[Sylvaen]

Great pics!
Here are some of Jasper that show how his pre-caudal gland blended in as he grew...

Jasper aged ~3 months old... starting to get adult fur along dorsal, pre-caudal gland is still noticeable:


Jasper aged ~4 months old... dorsal stripe is now obvious and guard hairs are coming in along back / down the length of his tail:


Jasper aged ~6 months old... guard hairs have covered his back and blended in along his tail:


Jasper aged ~2 years old... adult coat, full covering of guard hairs along back / body / tail, dorsal stripe is more blended and pre-caudal gland, while still noticeable, doesn't stand out like when he was a pup:

[Gaby]

Thanks for the explanations and the pictures!

i'm impressed with how u got the shot of the 1st pic to prove your point...

Haha, thank you! It was made because it was funny how she was digging, but I thought that people certainly would now what I meant. And I made some more pictures today to show it again. She is 12 weeks old tomorrow. You can see the black hair on her back, she looks already darker then the Tams shown above. Also the V thingy (thank you for naming it Nino ) is much darker then two weeks ago. (I'm so curious how she will look when she is grown up! )

[Nino]

your welcome

Sølves did get really dark and big before the other hairs started to make it seem less dominant on her