Hole-in-the-head (Head and Lateral Line Erosion)

Also known as Hexamitiasis, this parasitic disease can affect both fresh and saltwater fish. Lesions can appear on the head and flanks of the fish, hence the name: Hole-in-the-head.

This infection can also be responsible for head and lateral line erosion (HILLE) disease in fish.

Physical Signs

• Pale, eroding holes over the head
• Fish may look as if it is being eaten alive
• Coloration becomes subdued

Behavioral Signs

• Don’t often show until the condition is serious
• Can show general signs of lethargy
• May have trouble swimming due to a loss of balance

Pro Tip: Not all species of fish show the same symptoms, and do not always develop lesions to the same degree.

Potential Causes

Causes of this disease have been long debated, and nobody can say with certainty what the main trigger is.

However, the most accepted cause is the use of activated carbon in closed aquarium ecosystems.

Other factors can include nutritional deficiencies, especially key vitamins and dietary iodine.

Water quality can also play a role. Aquariums with high nitrate levels can cause fish to develop the illness.

Possible Treatments

If the infected fish has developed pale, eroding holes over its head, it’s in real trouble.

The open lesions provide an entry point for other pathogens which can cause further illnesses.

However, It’s possible for infected fish to improve when all activated carbon is removed and large percentage water changes are performed.

Improvements in nutrition have also been shown to benefit the fish.

Author – modestfish