The Temple Public Safety Facebook page posted the announcement, writing in part, "It is with extreme sadness and a heavy heart we announce K9 Chandler passed away today due to a medical condition."
The dog was 10 years old and had served the Temple community for six years, officers say.
There is no word yet on what the medical condition in this case was.
K9 Chandler worked with his handler, Temple Police Officer Natalie Sherman, every day, according to the post.
Officers described Chandler as selfless, brave, and a dedicated dog who spent most of his life in public service and community outreach.
"He was also a special member of our department family and holds a beloved place in all our hearts," the Facebook announcement read. "Please keep K9 Chandler and Police Officer Sherman in your thoughts and prayers."
A formal memorial service is expected to be announced next week.