Cow's nostrils turning black inside?

[EasyDay]

DH has noticed over the last couple of days that our cow's nostrils are turning black and the outside of the nose looks chapped.

Any idea what might be causing this?

Thanks

[Patt]

Dust? It's sooo dry and dusty here and then we have the occasional fire too it may just be from too much dust and dryness. I've never heard of any illness with that symptom. But there's always something new I haven't heard of so if it is a potential problem someone here will know.

[mtman]

thank-you she seems very healthy
i thought it might be just dirt allso