One caution about diagnosing fish diseases. Even with a microscopic examination fish diseases are not easy to diagnose. Most hobbyists have only what their eyes tell them to go on as to what any fish disease is. This means that diagnosis of any fish disease is simply a “best guess”. And these “best guesses” are frequently wrong. So keep this in mind in ALL the following symptom articles.
Unfortunately, diseases of fish do not come with signs saying things like “I have hexamita”. Therefore one must look at the symptoms. And one symptom can have several different “causes”. This is known as “multifactorial aetiology” by scientists. These symptoms are oftentimes termed “syndromes”. Each of these sections looks at the most likely candidates for any given symptom:
11.1. Hole-in-the-head Syndrome
11.2. Stringy White Poop
11.3. Malawi Bloat
11.4. Dropsy
11.5. Hollow Belly
11.6. Swim Bladder Disease
11.7. Shimmying
11.8. Twirling
11.9. Spinal Deformities
11.10. White Skin Blotches
11.11. Red Skin Blotches
11.12. Neon Tetra Disease
11.13. Slime Coat Disease
11.14. Scaly Skin
11.15. Fish Not Eating
11.16. Aggression
11.17. Black Death
11.18. Black Head Syndrome
11.19. Gas Bubble Disease
Note that there is one “symptom” which isn’t a “symptom”. Fish very commonly “flash” and “scratch” against the substrate and rocks. This is especially common after a water change. Unless they are doing this 100% of the time it probably is just an ich they had to scratch. It is nothing serious. If it is constant and really bad it can indicate chlorine poisoning, organics in the water, ick or flukes.
In addition here are some general articles that will be useful when treating any fish disease:
12.1. Basics of Treatment
12.2. Various Treatments Summarized
12.3. Quarantine Tanks
12.4. Ineffective Medications
12.5. Fish Don’t Drink
12.6. Sterilization
12.7. Making Medicated Food
12.8. Euthanizing a Fish
12.9. Avoiding Fish Diseases
12.10. The “Shotgun” Approach
These articles in turn are in addition to all the articles on specific diseases:
10.1. Diseases in General
10.2. External Protozoans
10.2.2. Ich
10.2.3. Velvet
10.2.4. Epistylis
10.2.5. Chilodonella and Costia
10.2.6. Tetrahymena
10.2.7. Cryptobia
10.3. Bacterial Diseases
10.3.1. Skin Ulcers
10.3.2. Mouth Rot
10.3.3. Duck Lips
10.3.4. Fin Rot
10.3.5. Saddleback
10.3.6. Red Blotches
10.3.7. White Eyes
10.3.8. Pop Eyes
10.3.9. Red Gills
10.4. Tuberculosis (Fish TB)
10.5. Hexamita
10.6. Flukes
10.7. Fish Saprolegnia or “Fungus”
10.8. Lymphocystis
10.9. Anchor Worms
10.10. Black Spot
10.11. Tapeworms
10.12. Nematodes
10.12.1. Camallanus
10.12.2. Capillaria
10.13. Pests in the Aquarium
10.14. Fish Lice
10.15. Dwarf Gourami Disease
10.16. Graphite Disease in Bettas
Startpage Aquariumscience
Source: Aquariumscience.org – David Bogert
