Hole In The Head Fish Disease – Precaution And Treatment

Freshwater fish are prone to suffer from a hole in the head disease. They include Oscars, discus, and cichlids. Mostly known as freshwater head and lateral line erosion or FHLLE, this disease has some causes that some owners can suspect before. Or else, they finally find the disease too late so their fish may die, due to the late treatment.

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Hole in the Head Fish Disease – The Causes 

There are several causes of this disease. Yet, the exact one might still need some test. But, somehow, many experts believe that the most exact theories which relate to such conditions might be just incidence. The existence of some factors that cause the disease has been studied by experts. But, some of them can be proven, while others still need further examination.

The most popular cause which occurs frequently is Hexamita. It is a flagellate parasite, that mainly causes the infection of the fish’s intestinal tract. The infection is spreading to some body parts like the gall bladder, kidneys, spleen, and abdominal cavity. When the infection is spreading, the hole lesions will appear in the head. Those lesions are opening up gradually which will result in discharging small white threads. They include parasitic larvae. 

Things get worse when fungal infections, as the ancillary bacterial will grow within those openings. They can lead to worsening conditions that lead the fish to die.


Fish needs nutrients. The lack or imbalance of vitamins and minerals can cause this disease as well. Many fish owners believe that there is a strong connection between the activated carbon that is used within the pool or aquarium can increase the chance of the disease because the carbon removes important vitamins and minerals within the water. 

Imbalance Minerals

At one go, the imbalance of minerals is also caused significantly by the existence of Hexamita organisms within the intestine. It leads to malabsorption so the fish cannot absorb their required vitamins and minerals.

Bad Water Quality

The disease incidence will elevate when the water tank or pool has certain conditions. One of them is the bad quality of water. Aquarists should replace the water frequently to keep it clean. 


Another cause of this disease is stressed fish. When an aquarium or a tank is overcrowded, then the fish will suffer from stress. Besides, this disease is infectious. Previous fish can be very contagious as the new fish might have a lower immune system.

The Symptoms

Hole in the Head Fish Disease

Newbies and experienced fish owners should know the symptoms. When they spot that the head and lateral line have lesions, then they should make an early treatment. This condition is still classified as mild. Yet, it gets worse when the environment is not good for the fish. The fish which is left untreated will suffer from severe infections, due to the spreading fungus and bacteria. Bigger lesions will produce worse infection eventually. When it happens, the fish will be ill, as it suffers from loss of appetite.

Treatments For This Disease 

Treatments depend on how the cause of this disease. Many experts make several approaches to the treatment. The main objection is to eliminate the Hexamita existence within the fish. Yet, some other precautions are to pay attention to the quality of water. However, when the fish still suffers from mild conditions, then they might need a higher amount of nutrients. 

The first treatment is by adding the antibiotic metronidazole based on the right dosage, within the tank. This is to ensure that Hexamita can be diminished gradually. The treatment should be done regularly. 

Another way to treat the fish that suffers from this disease is by watching the water quality closely. It is best to provide fresh foods for the fish, instead of preserved foods. Fresh foods don’t leave too much residue as preserved fish foods do. Fresh foods include seaweed strips or some kinds of vegetables like broccoli or spinach. Of course, fish owners should make sure that their fish are vegetarians, like cichlids. 

So, hole in the head fish disease is actually easy to prevent, as long as owners really pay attention to the overall treatment and maintenance of their fish. Prevention focuses mainly on reducing fish stress that is caused by the poor quality of water, the existence of parasites, and poor nutrition.

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