I have a 9 year old full Male GSD short coated,
For the last few months I feel his coat is getting harsher,there is plenty of oil on it (not overly bathed),but like's to swim in the sea.
I just wondered if any of you that show or know more about their coats had any idea's on what has caused it.
Is it a health issue ? or a age thing,
I rehomed him at 4 1/2 years old & he has never been happy being groomed (he thinks that he is being punished) So a brush once a week is a trial for him any more & he run's & hides .even with treats & his ball which he love's.
Any help please .

Well salt water wil dry out his coat, but his top coat ought to be harsh and weather resisting.

Is it just the texture or is his coat in poor condition?  The biggest effect on coat conditon will be diet.

He's on a raw diet,his motions are fine so is taking all the right things from it,He is fit & not overweight,It just feels the texture is odd.more wirey than I would think normal .
He only paddles so really not a full soaked doggie coming back fro the beach,well upto his lower chest not a dunk ,other long coated male is fine .

Is he getting enough Oils in the diet?

Raw mackeral ,tinned sardines,can you think of any thing else to add to his diet ? gets eggs now & again .

How about some salmon oil?

The sea wont adversely affect his coat - the only thing that I've seen do this is bathing, you say you don't 'overbath' him but how often do you?  I rarely/never bath mine, if they're really bad I take them to the sea to clean off....

you could try adding linseed oil to his food....

If it's only recent, have you had his thyroid checked?