So, the vitiligo defect doesn't appear immediately when the wolf is born, it should appear once the wolf is a few years old.
I do believe there is a vitiligo related bug going on though.. I was having a brain fart and couldn't remember the age where Viti spots start to show, so I looked up some vitiligo wolves in the trading post.
Stumbled across this girl, a vitiligo 1, four years old, and her spots are showing:
https://wolfplaygame.com/wolf.php?id=2011202
And right below her was this girl, a vitiligo 2, also four years old, but no spots are showing:
https://wolfplaygame.com/wolf.php?id=2057304
So, Serpents' wolf shouldn't have the spots showing anyways because 1 year old is too young, but I believe there's a bug going on with the older viti wolves.
Summer Month: 1 
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Earthquake Moon: 
