I am growing these this year, too! I have tried to grow these in past years, but this is the first year they have done well. I don't think mine have any spots on the leaves, I will have to look tomorrow. I probably would have done the same thing, better safe than sorry. I found a website that mentions some diseases these sometimes get, probably not for your area, but will give you more information:
http://www.omafra.gov.on.ca/CropOp/e...its/mouse.html