During the altercation, another woman sneaked up behind the man and unleashed Kira. The victim said he never saw the second woman and had no idea what happened to the dog.
The incident was captured on surveillance video. Deputies said the second woman is seen stealing Kira.
Hanson said Kira has a number of health issues, is hard of hearing and is going blind. He said he and his other service dog, Star, are distraught.
Anyone with information is asked to call deputies or Crimeline at 800-423-8477. Hanson said he is willing to give a $500 reward to anyone with information that leads to an arrest.