Need help with sick Ram

[Wat2Go]

Our Bolivian ram stopped eating. He swims around but his belly is really hollow looking and he is getting darker and darker. No visible signs (like ich or velvet or something like that) on him. The other fish don't bother him.
ANYTHING we can do to help him? Tried to hand feed him and he allows us to come close with food, he just won't eat.

[Nolapete]

sounds like internal parasites

[Wat2Go]

Anything we can do?

[yourchoice]

I picked out what i thought was a pair because the Lfs would not commit to picking a pair.Nine months later they spawn but the male ate the eggs.Three months after i originaly had them the female(which i wasn`t sure at the time)turned blackish and her belly was kinda yellow and fat..She did not eat anything for over 3 weeks.Now the male harrasses her all the time and she is blackish some of the time.I have 4 Dwarf rams and they do not get along .They are in 3 seperate tanks.
Try to get the fish to eat protein.Blood worms or Brine shirmp.