Over the years numerous things have been blamed as the cause of Hole in the Head disease in fish. While this is still a confusing subject among hobbyists one thing has become clear, the pathogen responsible for the ulcerated pits in the head and body of ornamental freshwater fish with this condition, is Spironucleus spp., in ornamental warm water fish, the culprit is typically Spironucleus vortens.
Water quality can often be a stress trigger among many species of fish, with excessive stress creating a lowered immune response which in turn opens the door for protozoa to proliferate to excessive numbers. No matter the stress trigger in each individual case, it is always some form of stress that triggers a case of HITH. Poor water quality, poor diet, stress from aggressive tank mates, overcrowding, etc, can all lead to an outbreak of S. vortens flagellates. With any type of illness, be it bacterial, viral, or parasitic, pristine water quality will help ensure a heightened immune response by the fish.
From the following paper;
http://scholar.lib.vt.edu/theses/available/etd-120399-140825/unrestricted/ANGEL.PDF
"In freshwater fish, Spironucleus sp. has been reported in cichlids, including angelfish, and cyprinids. Spironucleus elegans has been found causing disease in angelfish (Pterophyllum scalare) in Europe (Kulda and Lom, 1964b), while Spironucleus vortens has been also reported from the intestinal lumen of angelfish bred in Florida (Poynton et al., 1995). They can be found in the intestinal tracts of healthy fish and they may invade the body of the host and are capable of causing severe parasitemia under stress conditions (Molnár, 1974).
Hexamita are considered commensal organisms but can be pathogenic under various stressful conditions such as nutritional inadequacies, suboptimal water quality, crowding, poor sanitation and infections from other pathogens or parasites (Specht et al., 1989; Uzmann et al., 1965)
Although Hexamita and Spironucleus cause disease in several economically important fish species in many regions of the world, their pathogenicity is not well known (Woo and Poynton, 1995). It has been believed that the effects and the severity of diplomonad infection are dependent on fish size, tissue site infested, environmental conditions, stocking density, season and stress factors (Allison, 1963; Buchmann and Uldal, 1996; Mo et al., 1990; Uldal and Buchmann, 1996). Fish infected with Hexamita salmonis exhibited clinical signs correlated to their body length and weight (Uldal and Buchmann, 1996). This supports the study of Allison (1963) that large trout, more than 3 or 4 inches long, showed a smaller effect from Hexamita infection than smaller trout.
It is believed that the organisms invade the intestinal epithelium and disseminate to other tissues when the host’s resistance has been suppressed (Woo and Poynton, 1995). It has been suggested that only Spironucleus spp. cause systemic infection because they can invade intestinal mucosa and disseminate to other tissues (Siddall et al., 1992). Evidence of systemic spironucleosis was reported in cyprinids and aquarium fishes (Molnár, 1974), and in salmonids (Mo et al., 1990; Poppe et al., 1992; Sterud et al., 1997). In cyprinids, many Spironucleus sp. were found in the gut where they caused reddening of the mucous membrane, brownish-gray discoloration and necrosis of liver, and haemorrhagic enteritis. In aquarium fishes, the parasite has been reported to cause losses in angelfish stock of up to 50% of the population. The infected fishes showed reddening of the skin, and haemorrhages and ulcerations in the region of the head (Molnár, 1974). The parasites were found in the gut, gallbladder and visceral organs. Spironucleus sp. were also found in large numbers in the blood and the muscle of infected fish."
So from the most current research, we definitely know what parasite causes HITH, we know that these flagellates are typically found in the intestinal tract of the host fish, but they also have the ability to disseminate to other tissues and can travel to various organs, muscle tissue, blood of the fish, etc, in some cases ultimately causing ulcerations (pits) in the head region.
We also know some of the most effective ways to combat this specific pathogen (Spironucleus vortens), and there are a number of options available to hobbyists.
1.) The 3% epsom salt solution - http://www.monsterfishkeepers.com/forums/threads/treating-hexamita-aka-spironucleus.523470/ which while effective if the protozoa are still located within the intestinal tract, and the fish is eating (or force fed) once those protozoa travel beyond the intestine, into the blood stream, or various organs, it may or may not be effective at totally eradicating the parasite. My best educated guess is at this point this treatment alone will no longer be 100% effective, at least not in more severe cases.
2.) Metronidazole. One of the most effective medications used to kill this parasite. While the delivery is not always the easiest as its not overly soluble in water, and most fish do not find the bitter taste very palatable, it is still one of the most effective remedies available to the average hobbyist.
3.) Garlic - while much has been discussed about this substance over the years, there still remains much confusion as to its medicinal properties. Jack Wattley and Terry Fairchild first began experimenting with using garlic to treat nematodes in discus a few decades ago, and while they may not have been controlled tests that would hold up to scientific scrutiny, their results certainly weren't something that one could simply ignore. Since then there have been a number of controlled studies that involved various forms of garlic, including dry powder formulas, (not just concentrated allicin) which have proven to most definitely have a negative effect on various freshwater pathogens. Garlic and allium derived thiosulfinates, which are known for their broad spectrum antimicrobial properties, have been proven thus far to have a dose-dependant inhibitory effect on S. vortens. Some of these studies/papers are linked to below.
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.571758
http://www.ncbi.nlm.nih.gov/pubmed/21056027
http://omicsonline.org/spironucleus-species-economically-important-fish-pathogens-and-enigmatic-single-celled-eukaryotes-2155-9546.S2-002.php?aid=2762
http://www.ncbi.nlm.nih.gov/pubmed/22677132
A full read of the last paper can be found in the following link.
http://www.researchgate.net/profile/Kathirvel_Alagesan/publication/225282196_Disrupted_intracellular_redox_balance_of_the_diplomonad_fish_parasite_Spironucleus_vortens_by_5-nitroimidazoles_and_garlic-derived_compounds/links/0912f50be24e15257c000000.pdf
In which the authors summarize by stating;
"The overall cellular consequences of activated nitroimidazoles and garlic-derived compounds are similar in that they result in severe oxidative stress. Used in combination, these two classes of compounds might prove synergistic, thereby diminishing the metronidazole dosages required for effective parasite treatment.The extensive membrane blebbing observed after treatment with metronidazole, allicin and diallyl disulphide is intriguing and may indicate the presence of a programmed cell death pathway in S. vortens, initiated by gross cellular redox and ionic imbalances. However, this needs further confirmation."
Keeping all of the above in mind, if ones fish is still eating there is a simple way in which to get all of these substances directly into your fishes gut, and blood stream, where it can do the most harm to these parasites. New Life International came out with a new formula last year that along with their usual excellent nutrient levels, also contains Metronidazole, Magnesium Sulphate (epsom salt), and a mega dose of Garlic. While there are other metro based foods on the market, this is the only one that I'm aware of that contains metro, epsom salt, and a mega dose of garlic. The best part is this food really works! I have personally used NLS Hex-Shield on newly acquired fish that came in with clear signs of hexamita/spironucleus, as well as one very sick fish that ended up coming down with some deep pitting from HITH after fighting off a very serious bacterial infection. These fish all made a complete recovery after consuming this medicated feed.
If what some of the authors of the papers linked to above have speculated is true, some of these substances may work in synergy while causing a disruption of intracellular redox balance to the parasite, and provide a super cure for what's beginning to become a super bug. This new NLS formula may just be the answer that many hobbyists are seeking when attempting to cure a case of bloat, hexamita, or HITH. The fish that I cured of HITH would refuse to eat food treated with Metro, and would even refuse to eat his regular mix of pellets that were soaked in a 3% solution of magnesium sulfate. He took to the 3mm Hex-Shield pellets with no issue, and ate them for the prescribed number of days with his open sores healing and beginning to fill in shortly after. While my personal results may be considered anecdotal, it might be worth a shot for those that are not having success using more traditional methods of curing a case of HITH.
Cheers!
Water quality can often be a stress trigger among many species of fish, with excessive stress creating a lowered immune response which in turn opens the door for protozoa to proliferate to excessive numbers. No matter the stress trigger in each individual case, it is always some form of stress that triggers a case of HITH. Poor water quality, poor diet, stress from aggressive tank mates, overcrowding, etc, can all lead to an outbreak of S. vortens flagellates. With any type of illness, be it bacterial, viral, or parasitic, pristine water quality will help ensure a heightened immune response by the fish.
From the following paper;
http://scholar.lib.vt.edu/theses/available/etd-120399-140825/unrestricted/ANGEL.PDF
"In freshwater fish, Spironucleus sp. has been reported in cichlids, including angelfish, and cyprinids. Spironucleus elegans has been found causing disease in angelfish (Pterophyllum scalare) in Europe (Kulda and Lom, 1964b), while Spironucleus vortens has been also reported from the intestinal lumen of angelfish bred in Florida (Poynton et al., 1995). They can be found in the intestinal tracts of healthy fish and they may invade the body of the host and are capable of causing severe parasitemia under stress conditions (Molnár, 1974).
Hexamita are considered commensal organisms but can be pathogenic under various stressful conditions such as nutritional inadequacies, suboptimal water quality, crowding, poor sanitation and infections from other pathogens or parasites (Specht et al., 1989; Uzmann et al., 1965)
Although Hexamita and Spironucleus cause disease in several economically important fish species in many regions of the world, their pathogenicity is not well known (Woo and Poynton, 1995). It has been believed that the effects and the severity of diplomonad infection are dependent on fish size, tissue site infested, environmental conditions, stocking density, season and stress factors (Allison, 1963; Buchmann and Uldal, 1996; Mo et al., 1990; Uldal and Buchmann, 1996). Fish infected with Hexamita salmonis exhibited clinical signs correlated to their body length and weight (Uldal and Buchmann, 1996). This supports the study of Allison (1963) that large trout, more than 3 or 4 inches long, showed a smaller effect from Hexamita infection than smaller trout.
It is believed that the organisms invade the intestinal epithelium and disseminate to other tissues when the host’s resistance has been suppressed (Woo and Poynton, 1995). It has been suggested that only Spironucleus spp. cause systemic infection because they can invade intestinal mucosa and disseminate to other tissues (Siddall et al., 1992). Evidence of systemic spironucleosis was reported in cyprinids and aquarium fishes (Molnár, 1974), and in salmonids (Mo et al., 1990; Poppe et al., 1992; Sterud et al., 1997). In cyprinids, many Spironucleus sp. were found in the gut where they caused reddening of the mucous membrane, brownish-gray discoloration and necrosis of liver, and haemorrhagic enteritis. In aquarium fishes, the parasite has been reported to cause losses in angelfish stock of up to 50% of the population. The infected fishes showed reddening of the skin, and haemorrhages and ulcerations in the region of the head (Molnár, 1974). The parasites were found in the gut, gallbladder and visceral organs. Spironucleus sp. were also found in large numbers in the blood and the muscle of infected fish."
So from the most current research, we definitely know what parasite causes HITH, we know that these flagellates are typically found in the intestinal tract of the host fish, but they also have the ability to disseminate to other tissues and can travel to various organs, muscle tissue, blood of the fish, etc, in some cases ultimately causing ulcerations (pits) in the head region.
We also know some of the most effective ways to combat this specific pathogen (Spironucleus vortens), and there are a number of options available to hobbyists.
1.) The 3% epsom salt solution - http://www.monsterfishkeepers.com/forums/threads/treating-hexamita-aka-spironucleus.523470/ which while effective if the protozoa are still located within the intestinal tract, and the fish is eating (or force fed) once those protozoa travel beyond the intestine, into the blood stream, or various organs, it may or may not be effective at totally eradicating the parasite. My best educated guess is at this point this treatment alone will no longer be 100% effective, at least not in more severe cases.
2.) Metronidazole. One of the most effective medications used to kill this parasite. While the delivery is not always the easiest as its not overly soluble in water, and most fish do not find the bitter taste very palatable, it is still one of the most effective remedies available to the average hobbyist.
3.) Garlic - while much has been discussed about this substance over the years, there still remains much confusion as to its medicinal properties. Jack Wattley and Terry Fairchild first began experimenting with using garlic to treat nematodes in discus a few decades ago, and while they may not have been controlled tests that would hold up to scientific scrutiny, their results certainly weren't something that one could simply ignore. Since then there have been a number of controlled studies that involved various forms of garlic, including dry powder formulas, (not just concentrated allicin) which have proven to most definitely have a negative effect on various freshwater pathogens. Garlic and allium derived thiosulfinates, which are known for their broad spectrum antimicrobial properties, have been proven thus far to have a dose-dependant inhibitory effect on S. vortens. Some of these studies/papers are linked to below.
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.571758
http://www.ncbi.nlm.nih.gov/pubmed/21056027
http://omicsonline.org/spironucleus-species-economically-important-fish-pathogens-and-enigmatic-single-celled-eukaryotes-2155-9546.S2-002.php?aid=2762
http://www.ncbi.nlm.nih.gov/pubmed/22677132
A full read of the last paper can be found in the following link.
http://www.researchgate.net/profile/Kathirvel_Alagesan/publication/225282196_Disrupted_intracellular_redox_balance_of_the_diplomonad_fish_parasite_Spironucleus_vortens_by_5-nitroimidazoles_and_garlic-derived_compounds/links/0912f50be24e15257c000000.pdf
In which the authors summarize by stating;
"The overall cellular consequences of activated nitroimidazoles and garlic-derived compounds are similar in that they result in severe oxidative stress. Used in combination, these two classes of compounds might prove synergistic, thereby diminishing the metronidazole dosages required for effective parasite treatment.The extensive membrane blebbing observed after treatment with metronidazole, allicin and diallyl disulphide is intriguing and may indicate the presence of a programmed cell death pathway in S. vortens, initiated by gross cellular redox and ionic imbalances. However, this needs further confirmation."
Keeping all of the above in mind, if ones fish is still eating there is a simple way in which to get all of these substances directly into your fishes gut, and blood stream, where it can do the most harm to these parasites. New Life International came out with a new formula last year that along with their usual excellent nutrient levels, also contains Metronidazole, Magnesium Sulphate (epsom salt), and a mega dose of Garlic. While there are other metro based foods on the market, this is the only one that I'm aware of that contains metro, epsom salt, and a mega dose of garlic. The best part is this food really works! I have personally used NLS Hex-Shield on newly acquired fish that came in with clear signs of hexamita/spironucleus, as well as one very sick fish that ended up coming down with some deep pitting from HITH after fighting off a very serious bacterial infection. These fish all made a complete recovery after consuming this medicated feed.
If what some of the authors of the papers linked to above have speculated is true, some of these substances may work in synergy while causing a disruption of intracellular redox balance to the parasite, and provide a super cure for what's beginning to become a super bug. This new NLS formula may just be the answer that many hobbyists are seeking when attempting to cure a case of bloat, hexamita, or HITH. The fish that I cured of HITH would refuse to eat food treated with Metro, and would even refuse to eat his regular mix of pellets that were soaked in a 3% solution of magnesium sulfate. He took to the 3mm Hex-Shield pellets with no issue, and ate them for the prescribed number of days with his open sores healing and beginning to fill in shortly after. While my personal results may be considered anecdotal, it might be worth a shot for those that are not having success using more traditional methods of curing a case of HITH.
Cheers!
