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Why is my fish sinking and has a curved spine? What should I do?

Updated on September 23rd, 2025

Pet's info: Fish | Unknown - Fish | Female

For the last few months my fish sinks like a stone when she tries to swim and has a C-curved spine. I figured out a month ago there was too much phosphate in my water, so I fixed that, but other than that all my water parameters are normal. Her behavior is mostly the same, as she still tries to swim to you and eat, but last night she was lunging sporadically around her food like she couldn't see it. I don't know if she's suffering or if she's adapted, should I think about euthanizing her?

1 Answer

Most Helpful Answer

Todd Cecil

Answered By Todd Cecil

Veterinarian

Published on November 24th, 2019

Thanks for reaching out about Freddie. A curvature of the spine can displace the swim bladder making swimming difficult. Vitamin C deficiencies (scurvy) can cause spinal deformities and is usually the result of old food. Fish food should be purchased new every 2-3 months as vitamin C degrades quickly. A veterinary visit is recommended for radiographs to determine the status of the swim bladder and determine if antibiotics are needed. Radiographs might also determine if anti-inflammatories for spondylosis can help.
Good luck.
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