Help! My Goldfish Is Behaving Strangely
Of late, you noticed your goldfish behaving strangely but couldn’t be sure of illness let alone treat it. You aren’t alone, many fish hobbyists experienced this during their early stage of fish keeping.
- Does your goldfish have its fins clamped shut?
- Does your goldfish lurk in the corner?
- Does your goldfish keep rubbling itself all over the tank?
If your answer is yes to one or all three questions above, then your goldfish has a disease.
Most fish diseases can be treated if diagnosed earlier. Consult your aquarium dealer on how to tackle the ailment and take the necessary precautions when dispensing any medication.
Here Are Some Common Goldfish Ailments
Anchor Worms
- Symptoms: Tiny white, green or brown-red worm-like protrusions on open wounds.
- Cause: Mostly from live food or the pet shop.
- Treatment: Treat the whole tank with Dimilin or a copper solution from the pet shop to kill these parasites. Follow the instructions strictly. You can also use tweezers to carefully remove the worms.
Dropsy
- Symptoms: Swollen abdomen. Protruding scales. Eyes popping out. Pinecone appearance. Ulcers.
- Cause: Internal bacterial infection (acute dropsy). Cancer or internal parasites (chronic dropsy). Weakened immune system.
- Treatment: Isolate the sick fish. Use 1/8 teaspoons of Epson salts (not normal or aquarium salt) per five gallons of water to draw out the toxins. Buck up on cleaning the tank and ensuring good water quality.
Fin or Tail Rot
- Symptoms: Badly torn or frayed fins or tail with white edges. Stubs left in severe cases. Red streaks in tails.
- Cause: Stress. Injury. Poor eating habits. Too much ammonia, pH, nitrites in water.
- Treatment: Can be prevented by maintaining accurate water conditions. Best treated with a disease-specific antibiotic.
Ich
- Symptoms: Small white specks on body and fins that disappear and reappear. Fish scratches itself along tank or objects. Rapid gill movements. Cloudy eyes. Fin deterioration.
- Cause: Parasitic infection. Stress. Usually occurs with newly purchased fish.
- Treatment: Isolate the fish. Treat with malachite green or other medication recommended by the aquarium dealer. Treat the whole tank and wash all plants, filters, driftwood, etc. thoroughly.
Swim Bladder Disorder
- Symptoms: Loss of balance: swims awkwardly, upside down, keeps floating or stinking.
- Cause: Mostly diet-related. Improper water conditions. Wounds. Diseased internal organs.
- Treatment: Feed the fish a high-fibre diet with live and /or frozen foods and peas, in small meals three times a day. Avoid pellets. If that doesn’t help, you may have to treat for bacterial or parasitic diseases. Isolate the fish in another tank with shallow water. Maintain good water conditions.
Cloudy Eye
- Symptoms: Cloudy and whitish eyes. Signs of distress. Off-color appearance.
- Cause: Many causes, some bacterial infections.
- Treatment: Change the water more often. Treat your fish daily for a week: remove it by hand and apply a drop of silver nitrate to the affected eyes. Keep the fish out of the water for about 45 seconds before returning it to the tank. If you have charcoal in your filter, change it every two months.
Flukes
- Symptoms: Gill area is red and inflamed. Inner part of gill may protrude slightly. Gasping at the surface. Rapid breathing. Mucus-coated gills. Fish scrapes itself against objects.
- Cause: Parasitic infection.
- Treatment: Treat with potassium permanganate or fluke tabs.
With these tips, your goldfish is on its way to speedy recovery. 
Mermaid Highly Recommends:
Jun 16th 2008
5:01 PM
my goldfish is sick it at top of tank lot and its not eating nothing and is month does not open i thin something wrong with its month as my other fish month alway going i need help thank fish lover
Jun 21st 2008
6:22 AM
One of our pond goldfish is much larger than it was and its scales protrude a bit like a pine cone. It feeds ok and moves around ok but looks very strange. Is its appearance normal?
kind regards
Isobel
Jun 23rd 2008
3:25 PM
hi my fish had started getting the fungus/finrot about 1 week after they were put in the tank and i treated the tank with the medicine that was recommended. its been 4 days since the filters were replaced and water changed out partially and the water is still green from the medicine. the medicine turned the water a bright green and now it looks like a swamp. very ugly. do you know how i can get it back to clear? also im still concerned because there is still signs of bacteria on some of them.
Jun 25th 2008
1:37 AM
Hi Shawn,
Are all your fish affected? If only some, move them to a quarantine (hospital) tank. If all, move them too but you need to cycle your aquarium before moving them back (when they’re well).
This approach may be very cumbersome, but worth a try—move the affected fish to different quarantine tanks according to their condition stages. For example, fish that are in severe stage in one quarantine tank, and others that are mildly affected in another quarantine tank. Then treat them as accordingly.
Good luck!
Jun 25th 2008
1:42 AM
Hi Isobel,
It’s normal. More info. can be found here.
Feb 23rd 2009
10:08 PM
HELP!!!!!, i recently just started a fishtank (like yesterday) and just bought some koi.. but suddently today they look unactive and seems to have cloudy eyes.. there seems to be small white strain so something on thier body.. i have never treated fish and need to know what medicine for them..
Mar 24th 2009
1:19 AM
PLZ HELP!! I asked if my fish was fat and if he needed or she needed to go on a diet and was told its a GIRL and PREGNANT…I have no idea what to do with pregnant fish, i posted a pic of her and the link…to see it…
PLZZ HELP…DO i need to seperate her from the rest? She lives with 6 other fish..
Aug 21st 2009
9:59 PM
hi, my goldfish has been at the bottom of the tank mostly in one corner but swims around on that side of the tank. It looks like it has an inflamed gill but i am not positive. The gill looks like it has a red outline the pops out about 1/4 centimeter. I have just recently taken out the filter because her and another fish both had ich and i was curing it. I raised the temperature to 83 to help. Can this be what caused it? Please help!!
Aug 31st 2009
8:10 PM
hi ive had my goldfish for 2 months now and he is in abnormal positions and still breathing could he or she be pregnate?
Sep 6th 2009
6:08 PM
Hi, I have had my goldfish for about 6 months and he is usually a very lively fish. But the last couple of days I have noticed a change in his behaviour. He is floating near the bottom of the tank. His fins are moving but he isn’t swimming anywhere. He lurks around in the corner of the tank and his breathing is more rapid. He is still eating. And every now and again he swims around and looks almost back to his usual self, but his swimming stills seems slightly laboured. Please can you help? Thank you.
Sep 19th 2009
9:15 PM
so my fish had the ich and a started a salt and heat treatment. about two days into the treatment my black more began to have frayed fins. i found that it was a symptom of the ich so i just let it go. the ich is gone now and my fish’s tail isn’t frayed any more but the top tip is still missing. whats the best way to help him grow it back? will it heal by it self like the fraying?
Oct 11th 2009
4:24 PM
hi i bought my son 2 gold fish almost a year ago then about 2 months ago i got him another gold fish and an algae i have been noticing that 1 of the the 1s he got at first looks very swollen and swims very strangely i.e up side down on its side and banging in to the tank walls sometimes it just lies on its side at the top of the water then a week ago a noticed that the newer fish i got was missing and the strangely behaving fish had its skelleton in its mouth is this right ? can you please help thankyou
Nov 22nd 2009
8:06 PM
please help, my fantail fish have ich due to the introduction of two new weather loaches. I treated the tank with anti bacterial infection treatment as a precaution. Everything was ok but 2 weeks later they got ich and its really bad. All there fins are being eaten away and turning red. I did a 30% water change before applying the interpet white spot treatment at half the advised dose due to my loaches. Now they are looking more distressed and either sitting on the bottom of the tank or hiding behind the filter upside down. they are all still eating though… instincts telling me i need to do some more water changes but i’m worried it will weaken the medication. I have left the sponges in the filter but removed the carbon one. I just don’t know what else to do… please can someone help??
Jan 27th 2010
12:35 AM
Hi, Ive had my goldfish for several years now, and all of a sudden they are getting little white spots around the ends of their tails and their scales seem to be falling off… As of this morning they are dying fast… What can I do?
Feb 1st 2010
10:33 AM
Hi I have two goldfish that are about one inch long each and that I am currently keeping in a five gallon tank. The tank was only set up for about a week and originally for a different fish but I saw these two pathetic little guys at Walmart and I just couldnt leave them there. So the water quality is not as great as it should be in the new tank. Amonia is at .5. nitrate was 0, nitrite was right between 0 and .5. I have been doing about 30% water changes every other day to keep ammonia as low as possible while the tank cylces and I also added a bacteria supplement and a tablespoon of aquarium salt. I have a power filter and an airstone and the water temp is around 72.
So here is my question the fish seem to be going absolutely nuts swimming around back and forth up and down constantly but if I turn the filter off and the airstone down way low they begin to act normally again,swimming calmly. As soon as I turn the filter back on, wham they go nuts again. I tried to get them used to it the first couple days only using it for a few hours at a time but I dont want to risk it too much, the one also constantly attacks the bubbles from the airstone. I only have experience with our betta fish and he is much more low maintance so any help would be appreciated. Thanks