CHICAGO (CBS) — A Joliet animal shelter was asking for help finding a stolen dog who is in need of medication.

The 8-week-old puppy, a Shih Tzu-Poodle mix, was stolen from Hopeful Tails Animal Rescue, on the 200 block of Republic Street, just after noon Monday.

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A volunteer was walking out a door as two men were approaching the building. She believed they were volunteers as well, and let them in.

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Hopeful Tails board member Chris Ulrich said the two men grabbed a puppy that was in quarantine, and left in a car waiting outside.

“It’s very disheartening, because if they really wanted the dog, all they needed to do was speak up, and ask to adopt that dog when she became available. Actually, our adoption fee is probably less than it would cost them to get the same vetting that she would need done on their own,” Ulrich said.

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The female puppy was being treated for a respiratory infection, and needs medication, or is going to get sicker.