Anaheim police detained Walker, and her dog, at 12:03 a.m., after the 60-year-old ran a red light. When officials walked over to talk to her, she was instructed to take a field sobriety test, which she reportedly failed.
Law enforcement officials told TMZ that Walker's pit bull Petey was in the car with her at the time of the arrest, and was taken by animal control officials.
Walker was booked for misdemeanor DUI and was released within hours.
The former news anchor, who worked for local stations in New York, Los Angeles and San Diego, reportedly did a stint in rehab for alcohol abuse a few years ago.
Having been born with a congenital condition called syndactylism, Walker is also an activist for the disabled.