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My goldfish has fin rot and is laying on her side. What can I do?

Updated On September 23rd, 2025

Pet's info: Fish | Gold Fish | Female | unspayed

It seems like my black telescope goldfish has the beginning signs of fin rot. The ends of her fins are lightening and occasionally she is laying on her side. I used melafix tonight but i am scared she won’t make it to the morning. Any suggestions??

2 Answers

Most Helpful Answer

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Answered By Todd Cecil

Veterinarian

Published on February 20th, 2020

Thanks for reaching out about Pebbles. First, check water quality for pH, ammonia, nitrites and nitrates. Correct any problems as sub-standard water quality can lead to dermal (fin) damage. Melafix will not correct water quality and has shown little evidence to be effective. A veterinary visit can assess and help determine a diagnosis/treatment plan. Antibiotics added to the water are not absorbed systemically but might help with topical infections but a diagnosis should be made first. Good luck.

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    Answered By Todd Cecil

    Veterinarian

    Published on November 28th, 2018

    Thanks for reaching out about Kitty and including pictures. It does appear as it a trauma occurred to the fin, Secondary infections could surely be from the water column. Ideally, Kitty should be removed to a quarantine tank. Non-iodized salt can be added at 1 Tablespoon per 5 gallons for 3 consecutive days, to gradually build up the salt concentration. This will not provide an anti-bacterial level of salt but will help osmotically. Antibiotics should be used to treat the infection. These are best administered through injections but a veterinary visit would be needed to prescribe medications. Parasitic infestation can also lead to dermal erosions. Any new fish, invertebrates (snails) or live plants added in the last several months could be a source. Good luck.

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