This article was written to help people who are dealing with HITH, or just want to know more about it for whatever reason.

Additional input/comments is more than welcome. Let me know if i made any mistakes, too



Photo of HITH infected fish


WHAT IS HITH?
Hole in the head, or HITH (also known as HLLE- head and lateral line erosion) is an annoying common ailment in oscar fish, as well as many other cichlids. HITH 'creates' holes in the heads of larger cichlids. Why the head? Because HITH attacks the weakest spots- and sensory pits, small collections of tiny holes used to 'sense' stuff are located on the head. HITH also attacks the lateral line- a small series of indents that runs horizontally across both sides of the fish's body. (Because it is indented, lateral lines are weak spots, too) Once HITH has taken over these areas, it spreads, sometimes consuming the entire face of an oscar. However, most oscars die before this happens. Oh yah, HITH is fatal if not treated.


WHY DOES HITH OCCUR?
It is thought to be caused by the parasite Hexamita. However, Hexamita is a coldwater parasite that attacks the intestines of coldwater fish, and not cichlids. Studies done on cichlids with HITH show a percentage of 0 have Hexamita. Another contender is Spironucleus vortens, however tests done at the Vancouver aquarium on HITH infected fish demonstrate no signs of spironucleus. Some fish had it, others did not. A series of studies reveal that when discus and angel fish get HITH it is caused by Spironucleus, but when some other types of fish do it is NOT caused by spironucleus. Now, another flagellate known as Octomitus has been found in some HITH- infected fish. Both Spironucleus and Octomitus infect the gut of the fish (Hexamita does too, by the way), not the head or lateral line. So what causes the holes? Well, my guess is as good as yours. Somehow it is linked to these intestine-dwelling flagellates, I have no idea how, though.

SO, WHY DO FISH GET HITH IN THE FIRST PLACE?
Normally, a fish's immune system is strong enough to protect against HITH, but when a fish is stressed, the immune system is weakened and the fish succumbs to HITH. So, what causes the oscar to get stressed out in the first place? Well, there are hundreds of reasons, but there are four increasingly common ones that I will cover:

1) Poor Water Quality: This is the number 1 cause of HITH. If your nitrates are above 40ppm for extended periods of time and/or nitrites and ammonia are over 0. Fluctuations in pH and alkalinity can also cause stress as well.

2) Activated Carbon: Some fish in tanks with activated carbon get HITH, some do not. Why? Because it's not the activated carbon itself that causes the HITH, but the carbon dust. When carbon is transported, the particles rub together and cause the creation of 'carbon dust'. This can be removed by a thorough wash, but when people fail to do this, HITH often strikes up. But wait! That's not all, even if you wash your carbon well, you can still get HITH? Why? Because essential vitamins and nutrients present in the water are retained in the carbon, and this weakens the oscar. So really, just avoid carbon all together.

3) Poor Diet: An oscars diet is important. It needs to be varied, and should be based on a quality pellet. (Not sure what I mean? Read this article: www.oscarfishlover.com/index.php?option=...atid=13&id=26315 ) A good quality pellet is important, because generally they contain vitamins C & D, which when removed, can link to HITH.

4) Stray electrical current: It is important all your tank equipment is of good quality, because disfunction equipment could send out stray electrical currents causing stress to fish, and therefore causing HITH.

HOW CAN I CURE IT?
Have HITH and don't know how to cure it? Well first, make sure your fish indeed have HITH. (If your not sure, check out these photos: www.oscarfishlover.com/index.php?option=...atid=44&id=21691

Now, once you know your fish has HITH, do these steps:

1) Test your water. That means ammonia, nitrIte, and nitrAte and pH. If you don't have a test kit, buy one, or take a water sample to a local lfs- most will test for you for free. If your water turns out bad, do a 30% water change, and continue to do so daily. If your water tests fine (ideal parameters are ammonia: 0ppm, NitrIte: 0ppm, NitrAte: below 40ppm, pH: 6.5-8.5), do a water change anyways. Double check your water, too.

2) Remove all activated carbon, if you have any. Don't put it back in.

3) If your fishe's diet is poor, make it better. That means 50-80% quality pellet food, and the rest 'goodies' of your choice. Optionally, add 'fish' vitamins to your fish's food (they should be available at a local lfs).

OPTIONAL: Add tsp of aquarium salt per 5 gallons of water, and/or turn temp up 80-82 degrees farenheight. If you increase temp, add an airstone too because the oxygen is more dissolved in warmer water.

If all else fails, you may need to use medication. The most common medication (in the US) is metronidazole. Jungle Hole-N'-Head guard and Octozin both contain metronidazole. Metronidazole kills the flagellate parasites that inhibit the intestine of the oscar fish.


FURTHER READING:
www.worldcichlids.com/diseases/Adamhith.html
www.cichlid-forum.com/articles/oscar_cichlid.php
www.cichlid-forum.com/articles/spironucleus.php
www.fishdeals.com/fish_diseases/hole_in_head/


-Art

Thank you for the great post! I'm afraid my guy has it, it started as just a sensory pit seeming a little large about a month ago but it's def gotten bigger. My water quality is good and i do 30-50% water changes at least once a week. 55gallon tank. Oscar is about 5". ph 7.4-7.9, ammonia never over.125ppm (usually 0) nitrite 0, nitrate never more than 5.0ppm. Temp 80-82. The reading was very helpful, I just have a couple follow up questions. I have carbon filters now, can i take those out and have just the bio mechanical filter sponges that are in the pump until I get something else this week? And what type of filter do you recommend? I already do the salt as part of my normal water change. I don't have any tank lights on it, just the room lights, he seemed ok with that but maybe i should get some. i was waiting to get a new larger tank with everything included until this summer so i was putting off spending more money on this one. I'm going to try to pick up some of that metronidazole this week. My tank right now is in my classroom, taking it home this summer, he doesn't seem stressed out but maybe.... I don't know it's really fustrating to see it, i worry that it hurts!

imho i think that the best way to go in filtration depending on tank size is the canister filter. the main thing to look at when purchasing a canister is brand name and the rated tank size.
as far as brand name goes eheim, fluval, and filstar are in the top three in canister filters. the rated tank size when keeping oscars is twice the volume of the tank it is going on (if you have a 100 gallon tank look for a filter or filters that combine for 200 gallons) .

and i would recommend removing any carbon you have in your existong filter and replacingit with bio media.

just my 2 cents.

i concur with necro......

ok, thank you, aggravating though, i just bought more filter cartridges last week, i didn't know the carbon could be bad, it seems like that's what they push at the pet store. thanks for the advice!

saramat wrote:

carbon in the filter tends to misled the user. you are supposed to
replace them regularly; say after 100,000 liter cycle or 30 days use
depending in the load you are filtering. if you overlook that, then
there is a potential problem. in the fish keeping hobby, better without
it than risk against leaching back to the tank.

after medication, carbon is very effective in removing the rest
of unnecessary medicine but same precaution, remove when not needed
anymore.

Ok, I'm optimistic. Last night I picked up a Fluval canister filter (nixed the carbon) and API meds for HITH and some more variety foods. My wallet is NOT happy but hopefully the fish is.

I'm keeping my fingers crossed and hoping I started treating soon enough. He's still very active and happy so I'm hoping it clears up soon.

Any timeline you all have noticed for how long after meds and other changes before the holes shrink and/or disappear? I'd like to know how long to wait to see if I need to do another round of meds.

Does the medication your using contain metrodionazole? Medications lacking it often prove worthless, IMO.

Oh, and the BEST medication for HITH is WATER CHANGES! CLEAN WATER cures HITH BETTER than ANYTHING ELSE. Specifically nitrAte free water, high concentrations of this toxin seem to cause HITH faster than a similarily high amount of ammonia, and nitrIte, or so I've heard....

Regardless, water changes WILL help. So, watcha waitin' for? Go do one



that was a lot of caps... hehe

yes, it does have metrodionazole

my Oscars developed it about 2 weeks ago. I've tried doing routine water changes, giving them medication, and testing the water. The water is good but the fish are not. The medication hasn't helped at all. I'm starting to get worried I'm going to lose them what should I do?

What are your actual ammonia nitrite nitrate readings?
How big is your tank and what's the capacity of your filters?

I have two 30 - 60 gallon Whisper External filters running in a 55 gallon tank. I'll be honest I get my water checked at the local pet store because I'm friends with the owner. He told me they are perfect and I take his word for it.