Aquarium Fish Disease Guide: Symptoms & Treatments

It’s never nice when your beloved tank mates get sick. And although I pray you never have to experience it, it never hurts to have better knowledge and understanding on this subject.

In this article, we’ll discuss different types of common fish diseases, their symptoms, causes, and ways to treat your friends.

Let’s get started

DiseaseRepresentative Image
Bacterial Fish Diseases
Hemorrhagic Septicemia (Red Pest)Gold fish with red pest
Columnaris (Mouth Fungus)Red betta with Columnaris
Fish Tuberculosis (Fish TB)
DropsyGold fish with dropsy
Bacterial Fin RotFish with fin rot
Cloudy EyeGold fish with cloudy eyes
Swim Bladder DiseaseGold fish with swimbladder
Parasitic Fish Infections
Ich (Ick or White Spot Disease)Black moor with ick
Velvet (Gold Dust Disease)Fish with fin rot
Hole-in-the-head (Head and Lateral Line Erosion)Parrot fish with Hole in the head
Neon Tetra Diseaseneon tetra disease
Fungal Fish Infections
Body Fungusfish with body fungus
Cotton Fin Fungusfish with cotton wool
Viral Infections
True Worm Parasite Fish Diseases
Flukes (Skin and Gills)
Nematodes (Roundworms)fish with round worm
External Arthropod Parasite Fish Diseases
Anchor Wormgoldfish with anchor worm
Argulus (Fish Lice or Fish Louse)gold fish with lice


Prevention is the Best Form of Medicine

The ordeal of dealing with diseased fish isn’t fun for anyone. So the best way to ensure your tanks inhabitants live a long happy life is to create a healthy stress-free environment for them:


Nutritious Diet

A proper diet will do an excellent job of providing your fish with the range of nutrients it needs to to stay healthy.


No Dramatic Temperature Changes

Maintain suitable water temperatures with no sudden changes.

Fast changes in water temperature can be extremely stressful for your fish and compromise their immune system. We recommend investing is a quality heater and thermometer.


High Water Quality

Water quality is vital to keeping happy and healthy fish.

Investing in an efficient filter is key for removing debris and promoting healthy bacteria in your tank. Perform frequent water changes and use test kits to make sure ammonia and nitrate levels are safe.


Observing Your Tank

Monitor your tank regularly to ensure everything’s okay. Equipment malfunctions or deceased fish can quickly create a toxic environment for your fish.

It’s vital you catch and fix these problems ASAP.


Quarantine New Fish

When you purchase a new fish, make sure they’re free of all signs of stress and disease. Be picky and take your time making sure that they’re healthy.

And always quarantine a new fish for a few weeks to ensure it’s not going to contaminate your tank.


Please note: Even though we’ve extensively researched credible sources to provide you with the best information, what you’ve read should only be used as a guide. We’re not professionals with lab coats and clipboards. Always consult a professional if you have concerns about your fish’s health.