Miami-Dade County Animal Services is taking extra precautions to contain the disease, such as handling just one cat at a time, shelter spokeswoman Kathleen Labrada told The Miami Herald.
"It's scary because there are a lot of outdoor cats [in Miami-Dade county]," Labrada said, "and it's so contagious."
Labrada said the disease, first discovered in the area Oct. 4, can live in an environment for as long as a year.
Cat plague, or feline panleukopenia, is a highly contagious viral disease that affects a cat's immune system and gastrointestinal tract and is almost always fatal to kittens and young cats.
Intake at the shelter is operating as usual, but any cats showing symptoms -- lethargy, loose stools and vomiting -- are euthanized to prevent the disease from spreading.
"It's in the community so as long as cats are continuing to come to the shelter this is something we could be increasingly presented with," Labrada said. "The shelter is going to have to be extremely diligent."