A PAWS official said nine puppies from the same litter died of mycoplasma pneumonia. Their mother is doing alright and undergoing tests to see if she is a host.
Ten to 12 more dogs are sick with the same disease, but are doing OK so far, the shelter said.
Midwest Animal Hospital is assisting PAWS with intravenous medication, as antibiotics don't work on mycoplasma pneumonia.
The facility is being cleaned with bleach water.
Dog intake, viewing and adoptions will resume as soon as possible. Cat adoptions are unaffected.