A woman has suffered cuts to her neck, ear and back after a terrifying attack by a kangaroo while she was walking her dogs through bushland in WA's south-west.

Janet Karson of Deanmill near Manjimup, needed more than 20 stitches to her ears after she took on the kangaroo, which was attacking her dog.

"I went off the main track and suddenly this big kangaroo jumped out from nowhere and one of my dogs chased after it," she told The West Australian newspaper.

Ms Karson ran after her blue heeler and found it being bear-hugged by the kangaroo.

"I used a stick to lever its claws off my dog and then it reared up in front of me - it was huge," she said.