Who is Zeus' owner?

My dad had told me that he heard last week or a couple weeks ago either on Raceday or the pre race stuff that Greg Biffle owns the dog who plays Zeus that was also on the movie Marley and Me. Now I went on Greg Biffle's site and didn't see this dog pictured at all with Greg, his wife, or their other dogs. I am just wondering which dog on both movies is Greg's so I can get this cleared up.