GH-
Are the spots on the surface of the leather or do they appear to be underneath it? Where are they (toe, saddle, heel)?
Patent basically leather with a PU coating to give it luster/shine. I have found it is very durable. The only thing I can think of is that the leather have developed slight abrasions/nicks from play and there is dirt getting in there.
Pics would help if possible.
ML