Two questions about our springer spaniel

Question
Hi, I have a couple of questions to ask about our 1 year old welsh springer
spaniel.

Firstly, his coat is very dry and dull on the sides of his body, even though it's
shiny and silky everywhere else. We originally presumed this was because he
got wet every day (there's a big river where we walk him and he loves to
swim) so we now limit swimming to once a week. This didn't help much, and
the instructor at his obedience class recommended that we change his diet.
We switched from a rather cheap food to a much better quality one made with
all natural ingredients, recommended by the vet. However, neither of these
has really helped the problem. We were told by a friend that neutering young
(he was neutered at 5 and a half months) can spoil a dog's coat. Could this be
the problem?

Secondly, and this seems like a bit of a silly question, but how can we get him
more interested in playing fetch? We've encouraged him to retrieve since he
was tiny but he's always seen it as more of a chore than a game. He'll retrieve
as part of obedience training but out on walks he's not really interested and
he gives up after that first few throws. It's not a huge problem but it would be
a good way to burn off some more energy (he has tons!). He's a spaniel, so
shouldn't retrieving be "in his blood"?

Thankyou so much for your time, and sorry for the really long question!

Answer
You caught me in the process of rethinking my position on dog chow.  The dogs I see in real life are all thriving on inexpensive, common brands of dog chow.  The net is dominated by those that insist their dog must have an expensive, all natural diet.  I think much of it is in the breeding.  Having to feed the expensive, all natural diets appalls me, but fits some people's  world view.  They see no reason not to use diet sensitive dogs as breeding stock.  

There are several things that might work for your dog.  Most chows have plenty of fats in them to keep most dogs' skin and coat in good shape.  Some dogs need a little more.  You could try a teaspoon a day of liquid cooking oil.  Most of them are very high in the linoleic acid dogs need.  

You could try other brands of dog chow.  If you got the dog from a breeder, they may be able to advise you.  A good breeder will also factor in problems customers' dogs have in planning future breedings.  

Your vet may have started with the easiest possible cure, and have other things to try, such as checking the dogs thyroid.  

I don't have a good answer on the retrieving.  Perhaps you need lavish praise on him or even a treat each time he returns it.  As far as my puppies go, they seen to be more interested in me throwing the stick again than anything else.  

Note, I remember the way my one German Shepherd bested my nephew's German Short Haired Pointer at retrieving tennis balls.