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 which 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
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I have a Star Sapphire that had what I thought was a bacterial infection and fed him medicated food four fourteen days, tail stopped being clamped and grew back nicely, quickly. He still has this thing though, it started on his tail and has crept up his body, it’s almost like when you get sunburned and the skin peels and you can see the new and the old skin where it’s peeling. I’m not sure what this is, any ideas? Thank you so much in advanced, I’ve learned so much on this site!!!
In reply to Rebecca … Sounds like your bacterial infection isn’t 100% gone. I’d keep feeding antibiotics till it clears up.
Why do fish rub their bodies against objects in the aquarium after being fed pellets?
In reply to RYudis …. I have no idea why.
Hi Dave,
I hope you are well.
Do you have any idea what this is on the platty tail of the fish in the middle? At this stage, the fish is acting normal, eating, and not behaving differently. But this has developed. They are a squably bunch, but this looks a little odd, so consulting an expert!
Whats your thoughts?
Thanks,
Brad
In reply to Brad …. That is just a broken then healed fin. Pretty common.
Hi Dave,
That bit I showed you seems to have ‘fallen off’, and there is now a gap in the tail where that white bit was on the fish. Is that also normal?!
No other of the 30 fish have any fin rot-looking issues, and that specific fish does not have any other fin degradation – just where that white part was.
Time to panic?!
Thanks,
Brad
In reply to Brad …. Just ignore the broken fin issue and it will regrow.
Hi Dave,
I think its getting odd – I cannot work out if this is aggression or something else – see image below where the top seems to be missing.
Any ideas?
Brad
In reply to Brad …. That is fin rot on both the top and the back fin. The fish needs some antibiotic laced food. https://tankstartguide.com/index.php/10-3-4-fin-rot/
Thanks Dave. I feared that may be the case. In the UK access to antibiotics is hard for animal or humans. It’s going to be a challenge.
I am over filtered so upset that this occurred. Do you think I need to look at environmental issues as well? I.e. something else upsetting the balance that I should investigate?
Thanks,
Brad
Dear Dave
I hope you can help. I have a 2 year old angelfish who is laying on the bottom of his hospital tank. He had some white growths on him around his head so I took him out of my big tank and fed him medicated food with Maracyn (your recipe.) I also treated him with Para cleanse just in case it was a parasitic problem. The white growths are gone now and he looks perfectly healthy. He hasn’t eaten in about 5 days. He gets up, swims once around the 20 gallon hospital tank and then lays back down. When he sees me he gets up for a minute then lays back down. I don’t believe it to be swim bladder disease. Is there something that you can suggest?
In reply to Doreen ……. Just keep feeding the Maracyn and the Paracleanse. Note the prognosis with a fish that “lays down” is not good.
Hello Dave! I don’t know who else to turn to. I have a ranchu goldfish that previously suffered from dropsy and popeye, but thanks to your articles I was able to cure her when there was almost no hope left—thank you so much for that!
However, I have a different concern now. The fish has no obvious symptoms, she eats and sometimes swims, but suddenly she has started spending most of the day lying right on the bottom. Could this be a symptom of something, and is there anything I should treat her for as a precaution? She has never behaved like this before, and she is only a couple of years old.
In reply to Jeck Frost ………Like all fancy goldfish ranchus are very susceptible to swim bladder disorders. Nothing one can do about it. She can live a long life spending much of the time on the bed of the aquarium.
Is such behavior in itself potentially dangerous? Perhaps it would be worth giving antibiotics occasionally as a preventive measure? Thank you very much in advance for your answers!
In reply to Jeck Frost …………Antibiotics will do nothing for most cases of swim bladder disease. Just learn to live with it.
I’ll just leave this here in case it helps someone: the fish continued behaving like this for another 10 days and, unfortunately, suddenly died. It was an extremely sad loss for me, he was named Puk, a Ranchu goldfish :`(
I believe that if there were no previous signs of swim bladder problems and then the fish suddenly becomes passive (just lying on the bottom most of the day, while sometimes still swimming, eating, and staying upright), it’s worth starting a course of broad-spectrum antibiotics within 2–3 days, as recommended in relevant articles. It’s better than nothing