It happened between 3-5 p.m.
The puppy's name is Katy and she is a dachshund-terrier mix. The shelter says at this time it has no idea who took her. Investigators think the thief stuck the dog under their coat and walked out.
Katy had only been in the puppy room for a couple of hours and when someone came in to look at her, she was missing.
Officials told KBOI 2News Monday morning that the shelter has received no tips regarding the little pup.
Have information? Call 208-707-4663