A man who battered his grandmother's pet dog to death before throwing the animal's body at her has been warned he could go to prison.
Christopher Munns, 18, claimed he lost his temper after the Jack Russell terrier, Floss, bit him in March 2006.
Magistrates in Mildenhall, Suffolk, were told Munns had picked up a piece of wood with screws sticking out of it and hit the dog at least five times.
Munns, of Saham Hills, Norfolk, admitted causing unnecessary suffering.
Vet Alex Wylie told the court the dog would have been conscious and would have felt pain during its ordeal.
In a statement, she said the most severe injuries were to the right side of the chest where eight ribs were fractured in two places.
Michael Taylor, prosecuting for the RSPCA, said Munns had been staying with his grandparents in Brandon, Suffolk, when the attack took place.
His grandmother, Charlotte James, and his grandfather returned home to find the terrier dead on the floor.
Munns told Mrs James the dog bit his finger so he hit her on the head, the court heard.
Mrs James said in a statement she had told Munns he was not welcome in the house at which point he picked up the dog's body and threw it at her.
Asked why he had killed the dog, Munns told RSPCA officers: "All it had done was bitten me. I just got really mad with it. I don't know how many times I hit it. I hit it hard."
Claire Lockwood, representing Munns, asked for his guilty plea to be taken into account.
She said the attack was "out of character".
Magistrates postponed sentencing until 4 September for a pre-sentence report and warned Munns he could go to prison.