"Brutal attack -- he grabbed her and choked-held her and repeatedly beat her on the asphalt," said Donnelley.
Six a.m. Wednesday, Donnelley, who is a 34-year-old nurse, and Kokanee were walking in their San Clemente neighborhood when 26-year-old Bayron Reyes Lopez ran toward her.
"He went into a stance and started yelling and screaming at us," said Donnelley.
Donnelley believes Kokanee saved her life.
"She went out in front and by him focusing his aggression on her, it gave me valuable seconds, valuable time, to continue to yell for help," said Donnelley.
Neighbors called 911 as the suspect continued to beat the dog. Eventually he ran off, dropping Kokanee to the ground.
"Kokanee looked at me and she crawled three or four feet away from him and then just laid down on her side," said Donnelley. "I knew there was not much we could do for her, and so we just pet her."
Authorities say about 10 minutes after Kokanee was attacked up the street, the suspect showed up at the Rancho San Clemente Tennis and Fitness Club, where Lopez is employed as a maintenance worker.
Authorities allege Lopez removed his clothes and poured hot coffee and water on himself before being arrested.
"His behavior was extremely bizarre," said Jim Amormino, spokesman for the Orange County Sheriff's Dept. "We are looking into the possibility that he was under the influence of some type of drugs."
Authorities say Lopez lives across from where the attack happened. Deputies first tried to find him about 4 a.m. for playing a loud radio.
Hours later, Lopez is facing animal cruelty charges.
Julie Donnelley's family is grieving for Kokanee, the only pet their son John has ever known.
"She didn't deserve that. She was a good dog," said Donnelley.