Strange “lump” on Danio

[fishy_sean94]

For some time now I’ve noticed what looks like a red/black mark on one of my zebra danio fish.

When doing a water change today though and looking down at my tank I’ve noticed it seems to have grown a bit and become more of a lump.

None of my other Danios or other fish have any thing like it on them, and nothing has changed in the tank in terms of new additions for many months now so I don’t believe it to be something that it’s caught from something.

Currently he’s swimming normal, eating etc.

I’ve attempted to capture a picture of it but they move rather fast so it’s difficult getting a detailed shot of it.

I’ve had the danios for about 2 and a half years now so is it just a sign he’s on his way out?

 

[Rocky998]

@Colin_T might be able to help with this...

 

[Colin_T]

Looks like a big blood blister, which could be an infection, tumour or cyst.

The area around the red part is covered in excess mucous (creamy coloured area). Excess mucous would suggest an infection.

I would probably euthanise it simply due to the size of the red area and the age of the fish. You don't have to and can look after it until the fish has trouble swimming or stops eating/ acting normally, then euthanise it.

There's no treatment for cysts or tumours in fish. If you want to use a broad spectrum medication that treats bacteria and fungus (not antibiotics), you can try, but it will probably cost more than replacing the fish, and it might not work.

 

[fishy_sean94]

Poor guy

If it’s caused by an infection as you suggest it could be, do you have any idea how that could happen?
As I said nothing has been altered or added into the tank for months and all of the other fish are (so far) showing no signs of anything like it.

 

[Colin_T]

No idea how it happened. The fish might be older and weaker than the others. It might have scratched itself on something in the tank and it has turned into this. If it's a tumour or cyst, it happens in older fish and animals.

 

[fishy_sean94]

Thanks for your help.
I’ll just keep an eye on him for now then and see how he does.

 

[fishy_sean94]

Thought I’d update.
In the recent weeks it has gotten a lot worse and now looks like this:

It looks kind of “balloon/transparent” like so I assume is mostly likely to be a cyst rather than a tumour?

He’s still eating and swimming around, though seems to like to stay in the same area more now assuming due to the extra weight.

Would happily purchase some treatment for him if there was anything that could help, but I’m assuming particularly by this point there’s not much that can be done.

 

[Rocky998]

Ouch that looks painful... I don't have any recommendations on what to do sadly but hopefully someone will know what to do.

 

[Colin_T]

The fish has a bacterial infection (scales standing up around its body). Euthanise it asap.

Do a 75% water change and gravel clean the substrate every day for a week.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn.

 

[fishy_sean94]

Ah, sad to hear

I’ve done some research on putting him out of his misery and it seems clove oil is a top choice.
I’ve ordered a bottle of pure clove oil from Amazon but by the looks of it delivery won’t be for a few days.

As this issue has been in the tank for quite some time now with no sign of any other fish getting ill I’m hoping that means a few days waiting for this won’t put them at too much risk.

 

[fishy_sean94]

Also, I’m assuming as you didn’t mention any, no treatment of any sort would save this fish?

Just wanting to make sure before I do end his life.

 

[Colin_T]

I don't know of any way to save that fish.

I would wrap it in a couple of paper towels and hit it with something hard. If you can't do that, put it in a small container of aquarium water, pop a lid on it and put it in the freezer.

It's not fair to the fish to leave it with a bacterial infection.

 

[Essjay]

I’ve ordered a bottle of pure clove oil from Amazon but by the looks of it delivery won’t be for a few days.

Call in at the local chemist. They stock it - it's an old remedy for toothache.

How people used it for toothache I don't know, it smells horrible. Make sure you use rubber gloves to handle it as the smell lingers in the skin for hours.

 

[fishy_sean94]

I don’t like the idea of using brute force as feel being clumsy I’d probably not hit it in the right spot and end up causing it more pain and discomfort.

I also feel like freezing it would be extremely slow.

I’ve just gone to our nearby pharmacy and found this clove oil though to save waiting for Amazon:


The bottle doesn’t list any other ingredients so I suppose I’ll just have to assume it’s 100% clove oil.

 

[Essjay]

Yes, that's pure clove oil. If there was anything else they'd have to say since it's meant for humans to put in their mouths.