The dog's owner pleaded guilty to three charges at the Ballarat Magistrates' Court on Monday.

The Courier has chosen not to name the owner as she was not convicted.

She admitted she was the owner of a dog that attacked another dog causing serious injury, the dog was not securely confined to the premises and the dog was not registered with council.

A City of Ballarat prosecutor told the court a man stopped to let his 12-year-old greyhound cross out of his truck on September 20 in Redan, when the attacking dog ran out of a property across the road.

She said the attacking dog, which was eight-years-old, grabbed the victim's dog around the neck and thrashed it around.

The man managed to get it off and took the attacking dog back inside the house it had come from, where he found the front door open.

He returned to care for his dog that was bleeding from the neck and took it to the vet.

Representing herself, the attacking dog's owner told the court her dog was euthanised last week at the Ballarat Animal Shelter.

She said she had purchased the dog two months earlier from a breeder in Sydney who had provided incorrect information about the dog, including its age, previous owners and care.

The court heard on the day of the attack the front door blew open in the wind as one of its clips was broken, but this had not happened before.

The owner said she was in the shower at the time and was not aware the dog had escaped.

The court heard the owner was working to pay the injured dog's vet bills totalling $1500.

She decided to euthanise her dog because of the attack and the misinformation provided by its previous owner.

"We unknowingly purchased a tortured dog from kennels. We are sad we had to put him down... we're really sad this has happened," she said.

The City of Ballarat prosecutor told the court the owner had been extremely cooperative.

"This is all about if you have a dog, you have a responsibility to ensure dogs are secured so they don't attack other animals or people," Magistrate Noreen Toohey said.

Ms Toohey sentenced the owner to a two year good behaviour bond and ordered her to pay the vet bills and court costs of $127.

She said she took into account the owner's guilty plea and no prior criminal history in sentencing.

"Once you became aware of this you did everything you possibly could," Ms Toohey said.

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