Thanks for the warning but...here is a slightly less alarming post by a veterinarian:
It sounds like they aren't even entirely sure circovirus is the problem, and that the dogs had to be in close proximity to other sick dogs to get it.
Dr. Seuss~DLH (brother's cat)~June 2007-
Misty~DSH (my cat & Mooby's mom)-?-
MooBoots(Mooby) ~ DMH(Mom's cat)~July 21, 2008-
Sunshine~ Golden retriever X white german sheperd (Dad's dog)~October 24, 2008-