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."