"That's when the kangaroo actually leapt at me," Mr Rickard, 49, told The Age. "He did take a swing at me. That's what opened the cut above (my) eye. I thought that would be the end of it. I backed out with the dog, but the roo followed us."

The epic battle began when Mr Rickard and Rocky were walking on his Arthurs Creek property, about 45 kilometres north-west of Melbourne, and startled the roo, which Rocky chased into the dam.

The roo quickly got the better of Rocky and Mr Rickard plunged into the water to rescue his dog. When he brought Rocky to the surface, the dog's eyes were open but he was completely limp.

"That's not the behaviour of a dog that's still got any fight in it," he said, adding that 30 seconds longer "you've got a dead dog".

Mr Rickard said the roo then tried to push him under the water.

"The roo brought me down to one knee and half got me under the water but there was no way he had enough force to get me completely under," he said.

"While he was doing that I was still trying to make my way to shore and protect the dog. Attempting to push me under the water was where all the scratches came from."

Eventually, Mr Rickard made it to the dam bank with a motionless dog but also with gashes to his head, chest, arms and a deep wound across his abdomen.

"All the injuries were sustained while I was in the dam trying to pull the dog out," he said.

"A large gash above my right eye - all that blood left me unable to see. Then there's several large and deep scratches on my face, my neck, my back and chest, which are from the roo trying to push me down into the water."

Mr Rickard said he rarely had problems with kangaroos on his property. But this roo was an "aggressive male" and "unlike most kangaroos, which will stand their ground, this one was actively chasing the dog, which is something you don't normally see".