Tropical Fish Site

Profiles Reviews Guides for Tropical and Marine

Hole In The Head Fish Disease

Hole in the head disease is cause by protozoa and is usually a secondary infection. Low levels of the protozoa that causes hole in the head disease live within the fish, and poor water quality and/or poor diet leads to the infection.


  • Small hole or holes form in the head of the fish
  • Fish are white in colour and often have yellowish mucous trailing form them
  • Stop feeding


The fish should be isolated in a quarantine aquarium and then treated with octozin. Direct injections or medicated food are some other ways you could treat the fish.


As with many common fish disease, hole in the head can be cured by ensuring you do regular water changes and that your water parameters are as they should be with zero ammonia, zero nitrite and low nitrate (around 20ppm or lower).

Tropical Fish Site takes no responsibility for diagnosing the exact problem with your tropical fish, this is purely meant as a guide only. Be sure to look at other common tropical fish diseases to ensure you have made the correct diagnosis as there is often crossover between them.