A 14-year-old Winnipeg boy has been charged with first-degree murder in the alleged premeditated killing of his 79-year-old grandmother. The teen, who cannot be named under the Youth Criminal Justice Act, is also accused of killing his grandmother's dog by allegedly poisoning it.

Police were called to a duplex in Fort Garry, where they discovered the elderly woman's body inside the home.

The teen suspect, who police said didn't live with his grandmother but was known to frequent her home, was arrested at the residence and charged with the uncommon offence.

Winnipeg police usually charge homicide suspects with second-degree murder or manslaughter.

"First-degree murder implies intention to kill," Glover said. "There is indication this was a planned act by this male."

Cops allege the teen, who was in custody at the Manitoba Youth Centre, acted alone, with no accomplices. They said they have no other suspects.

The woman's pet, a small lap dog, was found clinging to life, a relative said.

"He poisoned the poor little pup. He put anti-freeze in the water dish," the relative said. "The dog was in agony for days. They took it to the vet to put it down.

"That's sick," the relative added. "It's bad enough to kill your grandmother."

Neighbours said the senior citizen went everywhere with her dog.

"She loved it to death," a relative said. "It's heart-rending."

The relative said she was the mother of the accused's father.

It is unknown whether the teen would be required to undergo a psychiatric examination.

The father wouldn't answer when asked whether his son had any mental difficulties.