A 66-year-old man has been killed and a 64-year-old woman seriously injured after his dog attacked the pair at their home in southern Tasmania.
Police and emergency services were called to the Allens Rivulet property about 10.40pm on Sunday after a neighbour heard the incident.
The man suffered serious injuries to his lower legs and was pronounced dead at the scene.
The woman was taken to the Royal Hobart Hospital with serious leg injuries and is in a stable condition.
"This is a family that had a loved pet. Unfortunately that animal has turned on them and it has had tragic outcomes," Tasmania Police inspector Colin Riley said.
Police have not released the names of the pair, who lived together, or revealed the breed of the dog.
It was euthanased at the scene at the request of police by an animal management officer from the local council.
"Decisions (to euthanise) are never taken lightly. Due consideration was given to the circumstances," Insp Riley said.
"We're very grateful no one else was injured, including our own staff and emergency services."
He said the incident would be thoroughly investigated by police in coming months and a report would be prepared for the coroner.
Kingborough Council general manager Gary Arnold said it was a tragedy for the rural community, which is about 25 minutes drive south of Hobart.
"I'd like to pass on our condolences to (the man's) family and friends," he said.
"We wish (the woman) a speedy recovery."
Two other dogs, one believed to be the same breed as the one that attacked, are being cared for.
Mr Arnold said it appeared the dog that attacked was not registered, but council records were being checked for confirmation.