The smallest puppies were clearly frightened. They were caged and malnourished.
Some of the larger dogs suffered eye and skin infections.
What rescuers found at a suspected puppy mill in Johnston, S.C. was nauseating.
Puppy mills are hidden operations run by people who market and sell dogs online.
The head of the Humane Society of the United States said the operators often cut corners.
The U.S. Department of Agriculture is considering a new rule requiring federal inspections to stop suspected puppy mills.
The rule would require inspections of nearly all dog sale operations. Right now, federal authorities license pet stores.
The new rule would open online operators to inspections.
Humane groups said they disapprove of online sales altogether because shelters are full nationwide.
Some cities, including Los Angeles, have stiffened their own rules outlawing puppy mills.
If the U.S. Agriculture Department decides to tighten protections for dogs, it would go into effect nationwide.