As I mentioned in the comments of my previous post, Martina Vannelli sent me photos of an oddly patterned Argentinian Polo Pony. I suspected at the time that he was another manchado. His spotting pattern is smaller and denser than that of the others I have seen, but I suspect that may be the effect of one of the sabino genes. Often sabino interacts with other patterning genes by breaking down the original pattern into smaller pieces.
His leg raps make it hard to see his markings but it appears that he has stockings on at least some of his legs. And of course his blazed face is typical of sabino.
We honestly don’t have enough pictures of manchado from enough angles to know exactly what it does, but given that it is primarily a top-down dorsal pattern (unlike sabino which is a bottom-up ventral pattern) I think that sabino might be redirecting the pattern somewhat on this horse. The markings here on the chest are a good example. It is a location that I would expect on a sabino, but the character of the patterning is a little different.
This is the angle that, to me at least, looks most like the manchado pattern. The round appaloosa-like spots is typical – just there are more of them, and each spot is smaller – as is the white tail. White tails seem to be a pretty consistent feature of the pattern.
I want to thank Martina for allowing me to share her photographs. And for those that just like to see pretty horse imagery, I highly recommend her Flickr account. She does beautiful work documenting the horses in Argentina.