Large white spots on goldfish tail

[MariaTeresa]

Now that the ice has melted and the fish have come up from the bottom or wherever they were hiding all winter, I've noticed that one of my goldfish has large white spots on it that appear fuzzy. At first there were three spots along the edge of the tail, but today I noticed more on the tail and some on the pelvic fins as well. The fish is about 8" long. When the algae bloom began she started gasping at the surface, but stopped after I hooked up the aerator and waterfall. (She seems to have damaged gills, as she will be gasping when all the other fish are happy as can be. I actually didn't expect her to make it through the winter!) The water is still only about 44F. I do not know the water parameters as I do not have a test kit. The other 3 goldfish do not appear to have any white spots and they act fine. I did fish out a baby fish (from last year's autumn spawning) that had fin/tail rot. I kept it inside with clean water and it recovered (but is still inside until the pond warms up).

In the picture you can see the spots on the tail. (Unfortunately the water is not very clear because I was moving some plants around and stirring up the sediment.)

Any ideas on what it might be? Fungal? Bacterial? The spots are too big for ich. Could the other fish 'catch' whatever is wrong with this fish?

[EDIT] Do you think it might be carp pox? That seems the closest I can come up with.

 

[Meyer Jordan]

It appears from what you have said that this fish's immune system was already compromised before the white spots appeared. The spots may very well be fish pox, but the underlying issue here is what has compromised this fish's immune system. Since pathogens are omni-present in all aquatic venues and generally opportunustic, water quality issues are usually the trigger. Test your water.

 

[MariaTeresa]

It will take awhile to get a test kit. My main concern is whether what the fish has might spread to the other fish. I wouldn't want it to spread while I'm waiting to be able to to test the water. All the fish had a day or two of illness when I added them to the new pond last year. Ammonia and nitrite levels were high due, I suppose, to the bacteria colonies not yet being established. I think this may have done permanent damage to the fish that is ill now, making it weaker and more susceptible to infection, etc. The white spots were apparent as soon as the ice melted. The gasping happened about a week later and was resolved with the addition of the aerator.

 

[MariaTeresa]

I went out to the pond this morning and a second fish is showing signs of illness. There is a small lump on its side and it is acting a bit lethargic. It is usually my most active fish, but it is just hanging out by itself a lot or with the fish that has all the white spots on it. I'm still waiting for the testing kit. I suppose all I can do is wait and hope for the best? The other two fish look and act fine.

 

[MariaTeresa]

Well, the fish died. It had been doing much better, the spots had gone away and it was more active, but last night it was so lethargic that I could just pick it up without it trying to get away. When I netted it out (dead) this morning overall it looked fine, except that its vent was very red/bloody.