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My goldfish has a big belly, not eating, sitting on bottom. Help!

Updated On September 23rd, 2025

My fancy goldfish has a huge belly, is sitting on the bottom of the tank and hasn't eaten in 3-4 days. What do I do?

1 Answer

Most Helpful Answer

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Answered By Angel Alvarado, LVT

Licensed Veterinary Technician

Published on March 3rd, 2019

Check the water chemistry and quality. This can be done by using a home test kit ( https://www.petco.com/shop/en/petcostore/product/api-freshwater-master-test-kit ) or by submitting a water sample for testing. The local Petco may do this for free or for a small fee. Aim for an absence (0 ppm) of ammonia and nitrites. Nitrates can be 20 ppm or less. Perform a partial water change if necessary. use conditioned water that is temperature matched to prevent additional stress or shock. Goldfish are cold water fish and do best between 65 F and 72 F. You can add plain aquarium salt (NOT table or Epsom salt) as a general tonic. Dissolve 1 teaspoon per gallon of water in a cup or two of tank water and gently pour it into the tank. It can improve gill function, reduce stress, treat minor infection and aid in any recovery. Treat for 14 days then reassess the condition. Perform more partial water changes afterwards to reduce salinity. In case he is constipated, you can offer bits of cooked and shelled green peas until defecation and swimming are normal. You can soak food in garlic juice to stimulate the appetite and provide an immune system boost.

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