A Toronto man has been found guilty of contributing to the death of his elderly mother by failing to properly care for her -- a case believed to be the first of its kind in Canada.

Donald Noseworthy, 55, physically and mentally abused his 78-year-old mother, who suffered from Alzheimer's and was bedridden and unable to care for herself, court heard. The senior was also kept near-starvation.

Noseworthy's mother died from congenital heart failure, but Justice Edward Then ruled the death resulted from the stress of being abused by her son.

The judge convicted Noseworthy of manslaughter and failing to provide the necessities of life.

"He didn't treat his dog that way and he had an elderly dog in the basement that he admitted to us that he fed, he changed the water regularly," Toronto police investigator Joel Kulmaticki said outside court.

"However, he allowed his mother to a live in squalor."

Noseworthy has been in custody for 19 months while awaiting trail. His lawyer argued that should be enough punishment.

"(The judge is) going to have take into sentencing all the considerations," Bill MacKenzie told CTV News outside the University Avenue courthouse.

"Mr. Noseworthy's not a threat to the public."

McKenzie said the court case is a rare one.

"The judge wasn't able to find any other case law in Canada that would support it," he said.

Noseworthy is to return to court March 2 for sentencing. He faces a maximum of 25 years in prison.

With a report from CTV's John Lancaster