The woman who took a Chihuahua puppy from the Pets Plus in Fairless Hills on Friday did not apparently know that the pup needs special care.
The pup is 10-weeks-old and a little over two pounds.
The woman was left alone in a pen with the white and tan puppy.
At some point, officials say she just walked out with the dog.
The puppy is on a special diet.
The staff at the store hopes that the thief just returns the puppy for its own sake, even if it's in a box left anonymously outside the store.