Emily6

Hey guys- maybe this is a question for a different forum but I figured you guys have always helped me before so why not try here first?

I have an older gold fish (aprox. 4 years old) who has a red bruise-like injury spreading across his head and back. I tried posting this last night but it didn't seem to go through.

Today, he got slimy and looks like he's sloughing off skin. I've had other fish go through this but none for very long before they died. They're usually older fish too. It doesn't look like any parasite or fungal infection I've seen in books or online. Though now his gill covers are starting to look worn away. All of his fins are fine (though he's clamping them- obviously sick). He's still eating a bit too.

His tank mate (another gold fish) is fine- even comforting it seems towards the sick one. Any thoughts? I'm dosing with Melafix and salt right now. I did a big water change too. I'm not sure if I should turn the heater on or not though.

dwalstad

Sorry to hear about your sick goldfish.

Recently, I did an extensive investigation on the prevelance of MB (mycobacteriosis or "Fish TB") in pondfish (goldfish and Koi).

The consensus of several prominent fish vets was that MB was rampant in goldfish (but not Koi). One study of 387 ornamental fish, showed that MB was more prevalent in goldfish than any tropical fish species studied. In addition, one vet/scientist wanting to use goldfish for experimental studies couldn't get a batch that didn't have some individuals chronically infected with MB.

If you can cure your goldfish with the chemicals and salt, consider you and your fish very lucky.

However, if you can't, I recommend getting a UV sterilizer. It will help with MB and many other diseases by decontaminating the water and reducing the fish's exposure to the number of potential pathogens. [Healthy fish can ward off a few potential pathogens but not a large number.] Remember, if you've got a sick fish in the tank, its releasing tons of pathogens into the water that will continously reinfect itself and other fish. The fish don't really have a chance in aquariums that recirculate the same old infected water.

Measures that I believe would help in your situation (no matter what disease the goldfish has) would be to remove the sick goldfish and get a UV sterilizer. In the meantime, I would do a massive water change to reduce the water's pathogen concentration. [The major route of MB infection is oral, so if you clean up the water, you've gone a long way to getting things under control.]

Big-time fish breeders recommend massive (50%) water changes every few days. I suspect that it is not only ammonia and nitrite that fish breeders are removing with those continuous water changes.

Fish diseases take a lot of the fun out of having aquariums. If you have an NPT and don't do water changes and the fish are doing great and don't have disease, fine. But if you've got disease problems, then I think you might want to consider a UV sterilizer.

For my own Rainbowfish with chronic MB, I hook up a ~$70, easy-to-use Submariner UV sterilizer whenever I see any problems in the tanks. Works like a charm!

Emily6

Thank you so much! That was incredibly insightful and explains a few things- namely, why his tank mate might not be getting sick despite the others falling to whatever this illness is. The tank mate is a Shurbumpkin. Fortunately, this is just a small 10 gallon I keep charity-case goldfish in without much time investment. So no plants to worry about.

Thank you again and I'll look into your suggestions. What are the symptoms of this fish MB? I'm sure my description reminded you of it somehow but I'd like to confirm. The symptoms seem very general right now, as far as fish illnesses go.

DataGuru

Emily: you're welcome to come over to theGab sick fish forum so we can trouble shoot what's going on.
http://thegab.org/forum/viewforum.php?f=4

Emily6

Thanks, DataGuru. Actually, this afternoon the sick fish looked almost completely better! No idea how that happened but I guess a 50% water change and some salt really did the trick (this time!). Anyway, I'm still going to look into the UV sterilizer since it could revisit my tank after this cycle. Thanks guys!

dwalstad

Glad to hear that your goldfish is better. I may have jumped the gun here.

Your goldfish may have just bumped into something or got caught somewhere and scraped himself. The slimy and sloughing off just could be the skin healing.

I wouldn't worry unless this one dies and other fish start having problems.

The salt treatment and water changes were a good idea.

nosoop4u246

None of the symptoms were conducive with fish TB, actually (darkening, anorexia, weight loss, spinal curvature)... Instead, I would guess it's a bacterial infection called septicemia, which will result in under-scale hemorrhaging and sometimes skin loss as a result. It often clears up sponaneously as its outnreans are very closely related to stress, which there is certainly no lack of if you have 2 Goldies in a 10 gallon tank! Each of those fish should be looking to reach about a foot in length, and the water quality and cramping associated with such large fish will make prevention difficult, and treatment even more so.