We have a goldfish in a ten gallon aquarium. We call her Goldie One. Three months ago she had a red spot by her head under the scale. It disappeared. We didn't do anything. Shortly after that, she had a red spot on her tail. We thought it will disappear but it became worst. The top part of her tail broke off. She seemed to be okay and perky.
Then, two weeks ago, the red spots reappeared. One on her remaining upper tail and around her mouth. The redness keeps getting darker. Goldie One's appetite is getting bad also. I took some pictures of her.
As you can see there is a red thick spot around her mouth. It's under the scale. There is no open wound.
On this picture, you will see the red spot on the upper part of her tail. The lower part is still attached but the upper one has broken off.
We did some research and we found out that our goldfish has a certain disease that is common to goldfishes. Her red spot is a symptom of a disease that is generally caused by bacteria.
According to Marquette University in Wisconsin, the little red hemorrhages under the scales of the goldfish is caused by a parasite called costia.
The Culprit
The parasite costia cannot be seen by the naked eye. It can be seen through a microscope in 100x. Costia looks like kidney beans. They move quickly and attacks the fish's immunity system. That's why it can cause other bacterial infections like fin rot or red hemorrhages.
Accoding to Ponddoc, costia is immune to salt. Therefore, salt treatment will not get rid of the parasite. A different method of treatment should be used to kill costia.
The Cure
When we learned about the disease, I thought it's the poor water condition. So I thought of replacing the water. But my husband said that we should avoid handling the fish because it might cause more injury. Any slight abrasion can be an entry point for bacteria to attack the fish.
Since the infection is rapidly progressing, we decided to buy an over the counter antibacterial medication. We went to the pet section of a the store and we found Melafix by Aquarium Pharmaceuticals.
Melafix is an all natural botanical extract of tea tree. As indicated in the directions for use, we need to remove the activated carbon from the filter if possible. Then we added 1 tsp for every ten gallons of water everyday for 7 days.
On day one, we removed the filter and put the medication. On day two, we've noticed that our foldfish is gasping for air in the surface. We thought that there is not enough oxygen in the water. So we put the filter back.
On day three, Goldie One's appetite improved. Her poop is no longer thin like thread. She's more perky and she approaches everytime we put food on the aquarium.
On day five, as I type this blog, her red spots are gradually disappearing. Her tail is healing. We are all happy about that. On the 7th day, we will replace part of the water.
Conclusion
I guess we found the right treatment for our goldfish. Our goldfish has been infected by bacteria and we used an anti bacterial fish medication. The parasite costia, caused red spots on our goldfish's mouth and tail. Melafix healed the red spots gradually.
As a word of caution, the proper diagnosis must be made first before giving any treatment to your pet fish. There are so many cures on different fish diseases and only the right remedy can help your fish. So do some research also.
And always remember to maintain good water parameters (levels of ammonia, nitrite, nitrate) in your aquarium. Fish can be affected by stressful environment. Give your fish some love!
