Mr Mussen and fellow senior firefighter Brett Pinnington were first on the scene at the blaze, which broke out in the laundry of the house.
While conducting a primary search of the premises for occupants, Mr Mussen found a cat unconscious in the master bedroom.
‘It wasn’t moving or breathing, so I carried it outside and immediately gave it CPR and oxygen,’ he said.
‘It had been overcome by smoke, but in under one minute, we had it on oxygen and it came back pretty quickly.’
The cat was handed over to other fire crews, which had arrived from Daglish, Osborne Park, Perth and Belmont while Mr Mussen conducted a secondary search.
He said they arrived ‘in the nick of time’ as the fire was starting to approach ceiling space.
‘Probably another few minutes and it would have got into the roof and it would have been a different story,’ Mr Mussen said.
‘I wouldn’t say I’m a cat lover, but I’m very happy.’