Fishguy2727
Aquarium Advice Addict
- Joined
- Sep 24, 2010
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I did A LOT of research on this based on primary scientific articles and the experiences of MANY aquarists. The article I wrote on this has been accepted by and will be published in Tropical Fish Hobbyist magazine.
One major issue is that since the symptoms are so similar (but not identical) almost everyone lumps HITH and HLLE together. Because of this when it is discussed you end up with people with discus who had HITH discussing it with people who have oscars who have HLLE.
There are primary research/scientific articles demonstrating that HITH in discus and angelfish is caused by Hexamita spp. and/or Spironucleus vortens. The symptoms are narrow, deep holes that may include white discharge. These holes are isolated to or directly adjacent to the head. HITH can be treated with metronidazole.
There is not much of anything outside of aquarists' experience with HLLE (in oscars, jaguars, severums, etc.). In these cases the holes are wide and shallow and do not include white discharge, but may extend well past the head along the body, usually adjacent to the lateral line. These cases do not react to metronidazole or other medications, but are treated with an improvement in the quality of the food and water. In some cases the aquarist thought they reacted to metronidazole or some other med, but they also improved the quality of the food and water at the same time (thus failing to isolate the medication as the cause of the improvement). Since it is not consistent that they react to medications independent of an improvement in the quality of food and water but they do very consistently improve when the quality of the food and water, it is well demonstrated that these are the main causes of HLLE in species such as oscars (although treating an illness is never 100%).
A few cases have shown that carbon filtration can cause HLLE. I talked to multiple aquarists who had cases go like this: They either acquired a fish that already had HLLE or one of their long term pets developed it. They tried improving food and water quality and even treated with meds, but nothing improved the condition. They hear of other theories like carbon filtration, so in desperation they remove the carbon filtration. Almost immediately (within days) the condition improves. After it has cleared up they try to get back to normal, or want to verify it was the carbon, so they return carbon filtration. Almost immediately (within days) the HLLE returns. Again they remove carbon and again the HLLE goes away. They do not return the carbon filtration and the HLLE never returned. This doesn't mean that carbon is THE cause of HLLE, it means it was the cause in these cases and should be considered in other cases if the condition of the fish does not react to an improvement in the quality of the food and water.
I am not trying to be argumentative or prove to anyone that only I am right. I did a lot of research on this so I would like to share it to get it out there. As we all know there is a lot of debate about the causes of HITH and HLLE and a lot of it has to do with how we think of these conditions (we think they are the same). The science is out there, the data from aquarists who have had to deal with it is out there. When I looked at this information it is clear that at the least they are not the same disease/condition. So yes, when it comes up I will share my opinion on the subject and discuss the shortcomings of some other theories if it comes up.
I hope this information helps people. This is a problematic issue in the hobby and the more people know, the more likely they are to help their fish. Maybe something about my theory is wrong, and I hope we figure it out soon, but based on the current information I think this is the most thorough explanation of these issues.
One major issue is that since the symptoms are so similar (but not identical) almost everyone lumps HITH and HLLE together. Because of this when it is discussed you end up with people with discus who had HITH discussing it with people who have oscars who have HLLE.
There are primary research/scientific articles demonstrating that HITH in discus and angelfish is caused by Hexamita spp. and/or Spironucleus vortens. The symptoms are narrow, deep holes that may include white discharge. These holes are isolated to or directly adjacent to the head. HITH can be treated with metronidazole.
There is not much of anything outside of aquarists' experience with HLLE (in oscars, jaguars, severums, etc.). In these cases the holes are wide and shallow and do not include white discharge, but may extend well past the head along the body, usually adjacent to the lateral line. These cases do not react to metronidazole or other medications, but are treated with an improvement in the quality of the food and water. In some cases the aquarist thought they reacted to metronidazole or some other med, but they also improved the quality of the food and water at the same time (thus failing to isolate the medication as the cause of the improvement). Since it is not consistent that they react to medications independent of an improvement in the quality of food and water but they do very consistently improve when the quality of the food and water, it is well demonstrated that these are the main causes of HLLE in species such as oscars (although treating an illness is never 100%).
A few cases have shown that carbon filtration can cause HLLE. I talked to multiple aquarists who had cases go like this: They either acquired a fish that already had HLLE or one of their long term pets developed it. They tried improving food and water quality and even treated with meds, but nothing improved the condition. They hear of other theories like carbon filtration, so in desperation they remove the carbon filtration. Almost immediately (within days) the condition improves. After it has cleared up they try to get back to normal, or want to verify it was the carbon, so they return carbon filtration. Almost immediately (within days) the HLLE returns. Again they remove carbon and again the HLLE goes away. They do not return the carbon filtration and the HLLE never returned. This doesn't mean that carbon is THE cause of HLLE, it means it was the cause in these cases and should be considered in other cases if the condition of the fish does not react to an improvement in the quality of the food and water.
I am not trying to be argumentative or prove to anyone that only I am right. I did a lot of research on this so I would like to share it to get it out there. As we all know there is a lot of debate about the causes of HITH and HLLE and a lot of it has to do with how we think of these conditions (we think they are the same). The science is out there, the data from aquarists who have had to deal with it is out there. When I looked at this information it is clear that at the least they are not the same disease/condition. So yes, when it comes up I will share my opinion on the subject and discuss the shortcomings of some other theories if it comes up.
I hope this information helps people. This is a problematic issue in the hobby and the more people know, the more likely they are to help their fish. Maybe something about my theory is wrong, and I hope we figure it out soon, but based on the current information I think this is the most thorough explanation of these issues.