White Saddle on Guppy

[frankfair]

I have a female guppy that has a large white patch of white mold looking stuff on her back just in front of her dorsal fin. This a solid white patch that extends from almost the bottom on the left side across her back and over half way down the right side. It is over 1/4" wide.
I have diagnosed this as cotton wool but wondering if anyone else has any ideas. I am treating with tetracycline (3rd day just started) but see very little improvement. Should I see improvment by now.
Water chemistry is great. Doing 20-25% PWCs prior to daily treatment.
Any other suggestions?

 

[mudraker]

Is she in a hospital or qt?

If not, she should really be isolated. Guppys can be awefully hard on each other when they see a weekness, especially horn-dog males.

Doesn't tetracyline turn the water red? If so, it may be hard to acurately see what is really going on with her . You won't be able to see changes in color of the infection, that kind of thing.

 

[frankfair]

The water is still clear but directions say do a 20% PWC before next daily dose.

I have been looking for bullying but just seems to be only more attempted sexual activity on the part of the males (but it seems she has a headach). She seems to be more active this evening and maybe the "saddle" is slightly better.

 

[frankfair]

Starting to get red tint to water after three days but bigger problems....

Now I am really confused!! My guppy has gone from just having a white saddle to being deformrd. She is bowed to the right and seems she can barely swim. I am getting ready toi euthanize her but am really worried that something is wrong with my tank.

I am getting a bunch of Lotsoffish's blue sword guppies tomorrow and am not sure what to do with them. I had planned to put the in this tank (I have removed the two angels). Nothing seems to be wrong with any other fish in that tank but I am worried.

I read that cotton wool is highly contagious and since none is showing on other fish maybe all will be well. Guess I will quarantine the blue swords until I learn more.

 

[BillD]

If the cotton wool is fungus, tetracycline won't help. Something like Maroxy, methylene Blue or Malachite Green, or another proprietary anti-fungal medication would be better. I would have removed the fish to another tank/container, added salt and applied MB directly to the wool. If you are worried about the tank, do a 50% or better water change before adding new fish. Quarantine for the new fish is a good idea, regardless.