I know a lot of you on here raw feed but for any of you that don't or who have recently acquired a dog or puppy I really recommend you use this site before you make any decision on what to feed:
whichdogfood.co.uk
For years we fed our lab x springer Baker's Complete (I know, I know 
) assuming that one of the most widely available dog foods couldn't be doing him any harm...
When he developed a lipoma at the age of 8 I discovered that diet was an important factor and that by changing his diet we could reduce the chance of him developing any more.
A friend recommended this site and were were appalled to discover the junk we have been feeding him for years.
We have since switched him to an alternative food (we chose Arden Grange Senior because it ticked all the boxes, is reasonably priced and is fairly widely available). It has a much higher meat content, is hypo-allergenic and has supplements such as glucosamine for his joints etc. The transformation in his behaviour is just unbelievable. He's happier, livelier, springier, glossier and, if I'm honest, naughtier 
)
I'm know to a lot of you I'm stating the bleedin' obvious but I just wanted to post our experience in the hope that it might be useful to other dog owners in future.