A police horse is retiring from the Minneapolis Police Department after 10 years of service. "Duke will retire Saturday night after his last shift with the mounted patrol unit. Police say the 15-year-old Percheron and quarter horse mix is beginning to show signs of arthritis in his back legs and it's time for him to hang up the saddle," KARE 11 said. "Police say Duke has been one of the unit's lead horses, and was so experienced that any officer could ride him. Police say Duke was willing to go through any obstacle, and could get other horses to follow," The Star Tribune said.