As your Lab matures you should know how to recognize a bloat, which can happen in an older Lab. I know because my old Lab, Jake, experienced a bloat when he was ten and survived. He lived another five years with no further problems. At the time I did not know anything about bloat but I was fortunate to be with Jake when the first symptoms appeared and got him to the Vet in time.
After Jake survived I did a lot of research and in 1997 I created a web page to help educate others.
Please take a minute or two to read about this condition at: http://home.flash.net/~jdebess/index.htm
Bloat is almost always fatal unless promptly treated so it is important to be able to recognize the symptoms.
I just lost my 10 year old to bloat last month, it was heartbreaking to see her in such distress. I most likely could have had surgery and cured the problem however she had many other issues that it wasn't fair to her to even try so I had her put down.
I miss my Boo-Boo girl but I know now that she's not in pain and hopefully she's in a better place.