Hi,
I was at my local aquarium today, looking at a couple of Oscars that were about 7-8 inches long, they were nice looking fish, but I noticed that one of them had several marks on the forehead, sort of like deep scratches or small gashes 1 or 2mm long that had healed over, but you could still see the healed scars, does this sound like the fish may have had hole in the head in the past? and if a fish has had this can they transfer it to other fish either when its raw or healed?
thanks for the help.

Yeah, sounds like they had hith or still do. They might just be scratched up, but i'm leaning towards hith. HITH is generally not contagious, but if one fish in a tank has it, the others are bound to aswell. However, if a fish with minor hith is transfered into a clean tank with hith-free oscars, the ones with no hith probably won't get it.

hth

-art

i agree wit art, sounds like hith....

healed wound, healed gashed, and healed early HITH could have same
feature once totally healed. HITH that had been healed is no longer
contageous. but the presence of HITH in a tank is very posible to affect
all fishes in the tank because HITH is a result of bad water condition.
the last that would be affected by HITH have the highest resistant to it.
if one has a HITH, the other would follow unless remidial water change
is in effect before it can damage the rest of population.