Does it smell musty, urine, feces, rotten, other?
Where is the goat kept?
Has he always smelled bad?
I assume this goat is not neutered and used for breeding. If so, he will leave an awful smell anywhere he urinates and even where he sleeps.
Get an enzyme product like natures miracle, zero odor or odor ban.
First hose off any smelly areas throroughly and then pour on the enzyme product.It is strong enough to neutralize male cat urine so it should work for goats as well.
Best of luck to you,