She's shedding out her winter coat now, and looked really grubby so I gave her a bath this morning. What I thought was "dirt" is actually a couple dark patches of back/brown hairs growing in a dapple pattern across her shoulders and rump. It appears to be typical to what I have seen with sooty palominos, but why didn't she have it last year? Can their be environmental factors?
I know very little about the history of the mare, I purchased her from a family who had picked her up at auction a few years before. I know nothing of her parentage, and only know she's had at least one foal (a bay) that was at the auction with her, sold as a yearling.
She's definitely in better overall condition and better fed than when I first got her. She wasn't seriously neglected when I got her though, just a bit rough, poor coat condition etc. but she had had regular wormings, dentals and care etc. I called her previous owners (we've stayed in touch) when I noticed it, and they don't remember her ever displaying such markings. I assume a sooty gene wouldn't normally fail to surface until at 10 years old?? Any thoughts about what is making them crop up now? (I'll get pictures on here as soon as she is dry)