The owner of two Staffordshire-cross dogs found bludgeoned to death on Saturday said their entire family had been "devastated" by the incident.
Kaleen resident Nerida Williams' two dogs, Rampage and Rush, were found dead lying next to each other on the side of Gungahlin Drive Extension near GIO Stadium.
A spokeswoman for the ACT RSPCA said both dogs were hit in the head with a blunt object such as a hammer.
"One of the animals appeared to have had injuries consistent with being hit by a moving vehicle in addition to the head injury," the spokeswoman said.
Speaking to The Canberra Times, Ms Williams said both of her beloved dogs were last seen at about 7.30pm on Saturday and were safe inside the backyard.
"To me, someone has murdered my dogs and left them beside the road like they were nothing," she said.
"Our backyard has fencing with no holes that they could have gone through and all gates had been thoroughly closed.
"Renovations had recently been done at the home, and in those five weeks of renovations, the dogs didn't leave the backyard with the gates being opened."
Upon discovering that Rampage, 8, and Rush, 4, were missing, Ms Williams searched the area around her home for the dogs to no avail.
She said she only found out about both her dogs being dead after a post on the Canberra Lost Pets Database Facebook page.
The Staffordshires were then taken to a nearby vet, where the cause of death was assessed.
It is not known whether the dog that was hit by the car was hit before or after being struck in the head.
"The vet said that the hole in their head was done by a single blow, and both of them had the exact same size hole in the exact same area of their heads," Ms Williams said.
"There is no way they both would have gotten out without a gate being opened."
The Kaleen resident said the family has been distraught in the days following the incident.
"I lost two children, and my son lost his best friend," Ms Williams said.
"They weren't just dogs, they were family members. We would treat them like they were humans."
The family had owned both dogs since they were puppies, and Ms Williams said they all had a close attachment with their beloved pets.
"They both loved going for walks and loved going in the car for drives," she said.
In the aftermath of the event, Ms Williams also contacted ACT Police about the incident, with the RSPCA also launching its own investigation.
Anyone with information on the attack has been asked to contact the RSPCA on rspca@rspca-act.org.au.