An Australian man was almost drowned by a kangaroo after he dived into his farm dam to save his pet dog.

Chris Rickard, 49, of Arthurs Creek, is being assessed by Austin Hospital surgeons after being mauled by the nearly 5-foot roo at 9 a.m. AEDT. He only managed to end the attack when he elbowed the kangaroo in the throat as it tried to hold him under water, The Herald Sun reported.

By then he had already suffered a deep gash across his abdomen as the kangaroo tried to disembowel him with its hind legs, as well as a deep gash across his forehead and further cuts and scratches across his chest.

Speaking from the hospital's emergency department, Mr Rickard said he was walking his blue heeler dog Rocky at the back of his property about a quarter mile from his home when they woke the kangaroo which had been sleeping in long grass near the dam.

The startled roo jumped into the dam, and Rocky followed. The roo then grabbed the dog with its front paws and held it under water for about 20 seconds until Mr Rickard arrived.

"I thought I might take a hit or two dragging the dog out from under his grip, but I didn't expect him to actually attack me,'' Mr Rickard said.

"I was stuck having to hold onto the dog with both hands because it was half drowned and I couldn't really see anything because the kangaroo just ripped into me.

"It was a shock at the start because it was a kangaroo, about 5 feet high, they don't go around killing people. Then all of a sudden I realised the first hit gave me opened up a wide gash above my eye and blinded me. I was flailing away underwater carrying a dog with a kangaroo ripping into me."

"All I could do was just keep pushing for the bank and he was trying to push me under the water, so at that point I elbowed him in the throat and that made him back off a little bit.

"I don't think I'll ever be able to watch Skippy quite the same as I used to—it might bring back a couple of bad memories."