Mystery Disease

[R3GG]

A few weeks ago i lost one of my 6 cardinals, i noticed it one day with its tail missing, a few days later it had gone down hill dramatically and died, i thought the tail could have been bitten off but i now have another one of my cardinals with tail problems...

I first noticed a problem when the start of his tail (nearest the body) had got a black patch on it, he still eats but has since got a small white dot on the black patch and his tail looks bent downwards slightly. I had to transfer all my fish to a small tank whilst modifying the large tank and this is when i noticed the black patch. Ammonia and nitrite are fine and i have tried using Myxazin and have added Stress coat. I do not believe this is white spot, there is only one white spot on the fish, he hasnt been itching or flicking against rocks and none of the other fish have white spots on them.
This is the best pic i could get of him before the light went off, you can just about see the black area:

I am trying my best to save the little critter, could someone please help?
Thanks

 

[nirvanarama]

this may be some kind of fungal infection, maybe fin rot?

what are your EXACT nitrite, ammonia levels? it could be suffering this because of poisoning.

 

[R3GG]

Ammonia is 0, PH is 7 and Nitrite comes out as less than 0.1mg/litre, if it was fin rot i would have expected to see an improvement with the Myxazin but there hasnt been

 

[nirvanarama]

hmmm this is a tricky 1.....

i would try messaging 1 of the mods as they have not come to your aid so far

 

[tstenback]

It may be saprolegnia, which can be treated with malachite green or other fungus med. The reason why i say it might be this is that it often displays a black color and accompanies other things likt tail rot. HTH

 

[R3GG]

Ok i'll try and get some med for saprolegnia, Thanks a lot for all your help, much appreciated

EDIT: Just read this on fishdoc.co.uk "Malachite green is reported to be toxic to tetras, catfish and loaches and small marine fish"

Do you think 'Tetra FungiStop' would do the trick? Details: "New stronger formula for the safe and effective treatment of fungal infections of fish and fish eggs. Additionally protects the delicate mucus membrane of the fish and promotes rapid healing."
Here are some more detailed pics...

 

[R3GG]

 

[R3GG]

 

[R3GG]

 

[Lateral Line]

I think it most probable that your Cardinals are infected with Sporozoan parasites. The most common of these is Pleistophora hyphessobryconis which is commonly called Neon Tetra Disease, (the genuine Neon Disease - there are a number of other things which often get called Neon Disease). Despite the common name, it has been found in several Characins, and even a few Cyprinids, including Zebra Danios.

The dark marks are decaying muscle tissue. The parasites themselves form cysts in the muscle tissue, (sometimes other organs), which as they grow, distort the spinal column. Your fish seem to closely match these symptoms.

It is infectious, and you should isolate the fish. There is no current cure for the disease I'm afraid.

 

[R3GG]

Thanks for the info, its more serious than i thought. I added some Protozin by waterlife this morning, when i got back from work all the cardinals and one of my corys looked very bad so i immediately did a 50% water change. Dont know why they didnt agree with the treatment. The fish are all looking better now except for the cardinal with the parasites and a couple of the other cardinals.

 

[Angry_Platy]

Neon Tetra Disease, (the genuine Neon Disease - there are a number of other things which often get called Neon Disease). Despite the common name, it has been found in several Characins, and even a few Cyprinids, including Zebra Danios.

Hmmm...I don't wanna hijack this post but from all the reading I did after I lost a fish to this, I thought that cardinals were immune to this....

Just curious

 

[R3GG]

Laterals description of the symptoms sounds very similar, i think he is right, if my cardinals have it then they cant be immune, just gotta work out what i'm gonna do now

 

[R3GG]

Ok, i have isolated the sick cardinal in another tank but i dont spose there is much i can do apart from hope the others arent infected.

 

[Lateral Line]

Yes, not much more you can do really.