okay here we go guys and gals. time for one of semper fi's book reports.

there are two different diseases referred to as hole in the head. one is caused by a flagellated protozoan, either hexamita or spironucleus and the other is environmental. the first is less common in the aquarium due to breeding. the symptons and sores caused by the disease differ. the end result can be fatal in both cases though. the first is so uncommon with the modern age of fishkeeping that it is rarely found any more. it is caused by the specific pathogen a flagellated protozoan. the protozoan is found in every fish in their guts and other organs. it is kept in check in healthy fish through their immune system. once a fish is weakened or environmental changes favor the protozoan, the numbers of the protozoans in the fish increase thus resulting in hole in the head (HITH). the symptons of HITH are the fish will lose it's appetite suddenly, will excrete white slimy feces and will develop puss filled holes in the head area. left untreated this can result in the fish's death.

the other HITH is caused by environmental stress. this is the most common form of HITH and can be an indicator of poor water and filter maintenance. this can be caused by an excess of fish waste in the water, but more than likely by the presence of heavy metals in the tank such as copper. more than likely in rocks that are gathered and not tested to be safe for the aquarium. the fish develops small open sores hat are not puss filled but rather like pits that can become enlarged as time goes on. this is caused by the epithelial cells dying. this can continue til too much of the head is exposed to the open water and the fish dies. unlike the other HITH the fish does carry on it's normal appetite and produces normal looking feces. there is no pathogen responsible in this form of HITH.

while the first HITH can be cured with meds, the second form will only be aggravated by th meds. the first step is to find out the environmental cause of the stress either poor water quality or the contamination of heavy metals. you will need to change the water atleast 75% every week to 10 days. remove any rocks that are not approved for aquarium use, ie out of your yard or found on the banks of rivers, lakes, etc.. another problem is the filtration of the water. if you choose a filtration system for a fish that is not full grown and do not regularly check that it is keeping up with the load of waste, this can cause excess waste in the water. aquarium filtration only slows the degradation of water quality it does not stop it.

from looking at your water changing schedule, you probably are experiencing the latter of the two HITH. the oscar is probably eating and pooping normally but he is growing. the water maintenance schedule was probably sufficient when he was younger, but now he is quite larger and you need to increase the frequencies of changes. once you get rid of the HITH you should continue the water changes on a weekly basis of atleast 20%. also make sure that your filter system is large enough to handle the amount of waste that is being produced by your oscar.

hth

maggie

Thanks Semp for posting this. I have thought my firemouths have Hith , all of them have small pin sized holes in their heads and one has large ones which I know is scar tissue from fighting.
The Water paramaters have always been fine and only one fish has died since (tiger barb, probably from annoying the firemouths) Do you think this is HITH?

if you could post a pic and let me know where it is. could be hith.