An elderly woman was killed after being attacked by an "aggressive rooster" while collecting eggs on her rural property in South Australia, a pathology expert has revealed.

Key points: Details of the death have been revealed by an Adelaide pathology expert

Details of the death have been revealed by an Adelaide pathology expert He says she was pecked in the lower leg by a rooster while collecting eggs

He says she was pecked in the lower leg by a rooster while collecting eggs He has sounded out how dangerous varicose veins can be for the elderly

The woman's death was studied by University of Adelaide Professor of Pathology Roger Byard, who said researchers hoped to prevent similar deaths in the future by bringing the details to light.

Professor Byard said the woman was collecting eggs from her chicken coop on her rural property in South Australia when the rooster pecked her lower left leg, causing her to haemorrhage and collapse.

An autopsy later revealed two small lacerations on her lower left leg, with her death the result of bleeding varicose veins.

"What we're trying to do is use these tragic cases to try and prevent similar deaths in the future," Professor Byard told the ABC.

The "aggressive" rooster attacked the woman in its chicken coop (file image). ( ABC News: Kieran Jones )

"[This case] made us realise how vulnerable the elderly are, [varicose veins] are very easy to damage.

"Older people are also not as good at defending themselves against animal attacks, their balance might not be as good."

The study — recently published in the journal of Forensic Science, Medicine and Pathology — focused on the dangers for elderly people who had varicose veins.

Varicose veins are twisted and enlarged veins which bulge above the skin's surface.

Professor Byard said the problem was that people with varicose veins could bleed very quickly.

"I've had a number of cases where people have just been wandering around in their home and just run into furniture which has caused a small injury," he said.

"They haven't known what to do and have died from it."

Rooster attacks 'extremely rare'

While Professor Byard admitted rooster attacks were rare, he said this case — which had happened recently — raised concerns about the dangers of small domestic animals.

Professor Roger Byard of the University of Adelaide.

"They are very rare, there have been a couple of cases overseas where children have been pecked by roosters because they have thin skulls and the rooster has actually caused brain damage," he said.

"There was another fellow in California who was at a rooster fighting pit and a rooster had a knife attached to its leg and stabbed or slashed him."

He said elderly people with varicose veins needed to understand they may be vulnerable.

"There are a couple of messages, one is never trust a rooster … the second one is if you've got varicose veins, get something done about it," he said.

Another case of 'leeches in their airway'

Professor Byard said he had come across a number of strange cases in his time, some of which had involved fish, stingrays and even leeches.

Professor Byard said he had come across cases involving leeches. ( Pixabay )

"We all know about bees and spiders with allergies and poisons," he said.

"There has been an array of strange cases reported from overseas of people drinking from water that has leeches in it and they've actually got leeches in their airway.

"[Also] fishermen mucking around putting fish in their mouths and they've actually inhaled the fish and died.

"We just have to respect animals, there is the potential that they can cause injury, particularly if you're older and more vulnerable."