The incident unfolded at about 12:30 a.m. Friday as officers responded to a report of an assault in the 13000 block of NE 70th Place, said Lt. Mike Murray of the Kirkland police.
The suspect had reportedly assaulted the victim with a broken piece of glass and was last seen fleeing the area on foot.
K-9 dog Thor and his handler, Officer Daniel Hopkins, responded to the area and began tracking the suspect. Meanwhile, another officer saw someone he believed to be the suspect in the 6300 block of 132nd Avenue NE.
A second officer responded to assist and inadvertently struck Thor with the front of his police cruiser, Murray said. Officer Hopkins was not struck or injured.
Thor was momentarily knocked unconscious. He was taken to a veterinarian and held overnight as a precaution, but is said to be recovering and in good condition.
The assault suspect was taken into custody and booked into jail for investigation of second-degree assault.