I don't know the meaning of "hith" but i think you mean the scars.. one of the owners before had a group of them and they all died except of him. I hope in a few months he won't have the scars any more.. but he's healthy and I hope I'll find a female for him.
The Uaru hasn't a disease. If you keep these species in a "bad" water they get wholes und scarbs. One of the owners before did that and in my water (PH 6,2) the scarbs are healing.