The North Carolina Department of Justice runs an animal welfare hotline at 1-855-290-6915. The link implies that this is a toll-free number within North Carolina only, so it may not work from where you are. If it doesn't work, the page above also mentions ways to file a complaint online or by mail. They also suggest contacting local animal control agencies directly to file a complaint, and provide a list of county agencies responsible for animal control.
When you file a complaint with this hotline, it will be investigated and forwarded to the appropriate authorities. It appears that it is typically the local authorities who will take action on such matters.
Our office will review your complaint to determine if the allegations involve animal cruelty. If our office determines that it is animal cruelty, then we will refer the complaint to the appropriate county authority in which the animal is located. Depending on the details of the complaint, your local animal control office, local Sheriff, or the NC Department of Agriculture may have the authority to take action. ... Complaints are referred to the proper county authority for investigation. Please direct follow-up questions to the county animal control or law enforcement agency.
Note that under North Carolina law, cruelty to animals is defined as when someone
intentionally overdrive[s], overload[s], wound[s], injure[s], torment[s], kill[s], or deprive[s] of necessary sustenance ... any animal ...
As used in this section, the words "torture", "torment", and "cruelly" include or refer to any act, omission, or neglect causing or permitting unjustifiable pain, suffering, or death.
It is not 100% clear to me that a breeder selling sick puppies would fall under this law, though if the worms were indeed caused by drinking tainted water that could be construed as "deprivation of necessary sustenance." In any event, it would be worth reporting this breeder to the NC hotline; they can probably make a determination better than most random folks on the internet (such as me.)