I have an el cheapo men-u brush, bought it new, and it is about 5 months old. The online store i bought it from said it was boar bristles, and the handle is plastic. About a month ago, i noticed little cracks around the rim, about 1/4 - 1/2cm each. The brush still works fine, but I am a little concerned about this development. I can't think of anythibg i'm doing with it that I shouldn't; I put it in a sinkful of hot water while i shower, dry it when I'm done and store it on the stand it came with. I clean it with the method described in the wiki.
Is there anything there a brush should not be expected to handle?