How long will my dog live for?

We had a purebred Great Dane live to 12 but most large dogs don't get that old with 7 or 8 not being unusual. However you've got a really good strong mix there (it works something like hybrid vigour with the gene mix being strong when it comes to stopping cancers) and I wouldn't be surprised if he gets to 14 if you can keep his weight reasonable and stress levels low. Read up on the signs for kidney disease and liver disease as it is these that are likely to visit a dog that's already reached old age; you can alter their diet to Senior and help take the pressure off those vital organs. May your dog live a long and happy life.