Loss of hair colour?

[Catherine]

I was just chatting with someone today who has taken on a pony that has distinct rings around its eyes and nostrils where the hair is markedly lighter than the surrounding chesnut colour.

I know that I have known what this is caused by in the dim past, but it just won't come to me. I don't think it's vitiligo or anything like that, as the skin itself is unchanged in colour. I'd know it was a copper deficientcy if it happened to my cows, but not for horses!

Can anyone remember what it's caused by?

[lleeaannee]

no idea but ponyvet might know!

[Piaffe]

Is this pony arab/arab cross? I believe it is due to copper deficiency - my friend's arab used to suffer with dark rings around his eyes which were hairless, but only at certain times of the year.

I wonder if it is the same sort of condition?

[ponyvet]

Actually people used to think it was relate to copper deficiency, but I believe that's not so. Although copper is a vital component of melanin, the hair pigment, deficiency in the UK is actually quite rare, and only seen in ruminants, which are very susceptible. However horses are less susceptible, but show problems relating to bleeding (nasal bleeding especially) in adult horses or developmental problems in foals. It's currently thought to be part of the OCD problem, but nobody is quite sure yet how to sort it out, since too much copper is a problem too.

ANyway back to the horse. Arab horses actually suffer from a genetic disease called VITILIGO. This incidentally can be found in humans, and is what Michael Jackson says he has.

In arabs the hair typically changes colour, and becomes pale, around the mouth and nostrils, and eyes. This colour change may come and go, becoming lighter or darker, especially with the seasons. It sometimes only shows in foals, and they grow out of it, or it shows up as they get older.

It's related I think to the ability of the skin cells to store the pigment. Normally the hair will pick up the pigment from the skin as it grows, but if for some reason the skin cannot provide the melanin the hair will be pale.

In these horses there are no other signs of skin problems, no itchiness or flakiness, nor are there any other apparent health problems.

There is no treatment, but it's only a cosmetic problem.


Circular hair loss is slightly different, and may have been the same "Arabian Fading Syndrome" but could also have been a photosensitisation.

[larri]

Could it just be a simple winter coat change?
I say that because safi who is bay roan and has a black muzzle in summer goes completely white under her eyes and muzzle in winter. Would the previous owner know if it was regular??

[Barkless]

Can you post a pic of the pony?