Chris Klein's dog helped him realise he was an alcoholic.
The 33-year-old 'American Pie Reunion' actor - who entered rehab in 2010 after being caught drink driving for a second time - admits his German shepherd Chief knew he had a problem long before Chris did.
He explained: ''He would get agitated that the alcohol was coming out, and I will be forever grateful to him for that.
''He began to recognise the behaviour shift In Me when [I drank] alcohol and his behaviour would change.
''Anybody that has a meaningful relationship with a dog will understand that the disappointment that I saw in his eyes, [it was] insurmountable.''
But things came to a head when he was pulled over while driving under The Influence with his beloved dog in the passenger seat.
He told People Magazine: ''I drank away anything and everything that was at home. I had nothing to come home to. My beautiful, wonderful dog was taken care of, he didn't get hurt, he didn't even have to go to the pound that night. They allowed me to call a friend of mine in the area to pick up my dog.''
Now 19-months sober, Chris is living life to the full and still has his best friend and saviour in tow.
He added: ''On a Sunday I don't wake up hung over.
''I sit in my dining room with the sun coming in through my garden. Then it's Chief and me for the day, jogging on the beach, hitting the hiking trails.''