Goldfish and constipation

All fish can potentially suffer from constipation, regardless of the type of diet they are fed, and goldfish are no exception. As goldfish are prolific eaters, constipation is one of the more common problems they face.

So, if you’re wondering how to tell if your goldfish is constipated – and what you should do about it if so – then read on to learn more about constipation in goldfish.

What is constipation?

Constipation is a blockage of the digestive system, which makes it difficult or impossible to pass feces naturally and comfortably.

The blockage usually occurs in the bowels or intestine, and will form a hard mass of compacted waste that the goldfish cannot expel from the body normally.

This leads to extreme discomfort and in chronic cases, can even cause death.

Symptoms of constipation in goldfish

You can usually identify constipation in goldfish by the appearance of the fish; they may appear physically bloated, and may also be trailing a string of feces behind them that does not drop off as normal.

They may also have problems swimming normally, and appear very lethargic, as well as losing their interest in food and possibly showing signs of discomfort.

What causes constipation in goldfish?

Generally, constipation in goldfish (as with other animals) is caused by feeding a diet that is not completely balanced, and lacks enough roughage or dietary fiber. Fiber is important to help the metabolism to keep moving, and to bind the food so that it can be passed naturally.

Goldfish that nibble live plants within the tank will rarely suffer from constipation, and it usually occurs in fish that are fed a diet high in protein with not enough roughage.

How can constipation in goldfish be treated?

Generally, constipation in goldfish can be resolved by upping the amount of dietary fiber in the diet and promoting the consumption of greenery and roughage.

You should stop feeding your fish pellets or flake food while you resolve the issue, and concentrate on encouraging them to eat plant matter and greenery. Tinned peas (sugar and salt free) are a good product to feed to a constipated goldfish, as they have a gentle laxative effect.

If your goldfish is not eating at all due to constipation, you may need to isolate the affected goldfish and add a dose of Epsom salts to your hospital tank at the rate of 1-3 teaspoons per 5 gallons of water. This relaxes the muscles and aids in the passing of faeces.

20 thoughts on “Goldfish and constipation”

  1. I’m not sure if my gold fish has dropsy or constipation. Swimming about as normal. Still very lively. But because of the swelling in stomach I stop feeding it pellets and gave it greens. If I was to email you a picture could u help advise me on what to do ? Please and thank you for reading this

    • Hi Sharon, we’re happy to receive a photo via the Contact Us page. From what you’ve said, we suspect constipation or a swim bladder issue are more likely than dropsy. Dropsy causes a fish’s scales to stick out – people often describe this looking like a pine cone – so you’d be fairly easily able to spot it if your fish had it.

  2. I need help figuring out what is wrong with my mother’s 8 year old fancy goldfish. He’s extremely bloated looking and goes between being interested in food and then not interested. We have tried peas he doesn’t touch them and she’s been trying Epsom salt but all she has noticed is that he gets a little more active for a short period of time. No idea what is going on.

  3. Heyy
    My fish has been sitting at the bottom of the tank during night. I thought it was common, that it’d be sleeping. Whenever I approached it, it’d come to the top like usual. But today (26/09/21) it has sat at the bottom for a long time and swims weirdly. Sometimes it becomes slightly tilted while swimming and just now it was on the verge of swimming upside down. Whenever it’d sit, it’d kind of sink down and bounce a little as a result. It has been a week that we changed the tank, the fish was fine and happy but this started happening today and I’m extremely worried about it. It’s also not eating much. Generally, it’d come to the top Whenever I opened the lid of the tank, but today evening it didn’t eat well. It’d also suddenly start swimming rapidly, hit its head on the walls or smth and then sink down.. Our tank does not have any stones, it’s empty with two artificial plants. Will feeding peas work? Please suggest something as soon as possible.

    • Hi, thanks for your message. How big is your tank? Have you tested the water parameters (and if so, what were the results)? It sounds like a swim bladder problem, though without knowing more – e.g. whether the fish is in a very small tank with high ammonia levels – it’s difficult to identify an exact cause.

  4. I have 2 black fish.and 1 gold fish.i have lost 1 of swims side ways.and sits in the same corner all wont ear.and it tonite I notice it has moved to the other back side of the rank.any reason it would be doing this?

  5. My poor old 1-11/2 pound goldfish just died. I have had him for nearly ten years. He died of dropsy. He was swollen well over two years when it finally died. At first, I thought it was pregnant. Then after a few months, I started researching the problem. No doubt it was dropsy. I can’t believe he lived so long. I guess he was going to die at some point, but it’s funny how attached one can get to a durn fish. I am a gardener. He is now peacefully adding minerals and such to my compost. I dug a deep hole in the compost, covered him with lime, and buried him so nothing would smell him and dig him up. He will make some good tomatos!

  6. It’s sad to lose them . I’ve just lost my treasured comet goldfish of 24 years. He had a tumour removed some years ago …successfully and he had many lovely years of life so I thought he would go on and on. he developed gall bladder disease 3 months ago. swollen and living on the bottom of the tank . he was treated with anti-biotic by a vet for the whole time and the inside cooled down of green peas mostly with a few flakes. he did well but remained on the bottom . Finally this last weekend he showed large white patches on his body. He did not survive those.

    • Hi Rosalie, thanks for your comment,
      sorry to hear about your loss, sometimes there is only so much we can do to prevent health ailments, 24 years is quite old, sometimes it can be too much stress on their bodies.
      Your methods however, are really good for anyone else in a similar scenario, green peas and anti biotics can be a good remedy for internal illnesses in goldfish. Thank you for sharing.

  7. what is the best antibiotic for goldfish with swollen bellies? my 5 year old comet is so bloated but eating and swimming. I’m afraid he’ll explode he’s so large. I have melafix and lifegaurd on hand. Are either good? Thank you

    • Hi Diane, thanks for your comment,
      It is very common for fish to continue to eat even when bloated, even if there is blockage within their gut, which it sounds like there may be.
      Fish can and will eat themselves to death, I would recommend you stop feeding your goldfish for a few days, as more food at this stage will add to the problem.
      Melafix is an excellent product and I always highly recommend it, as it is a natural herbal substance with great effects.

      Just be aware, that dropsy and bloat isn’t easy to cure, in some cases the fish can overcome it on its own, but sometimes there isn’t much that can be done once the fish reaches a certain stage.
      Using Melafix and fasting your goldfish may help, you can even try Epsom salts to assist with bloat, but they arent a guarantee to fix the condition, as bloat isn’t always bacterial and can be caused by a number of things.
      I hope this helps, and good luck with your comet.

    • This sounds like typical constipation or bloat symptoms.

      try fasting your goldfish for a few days to see if the swelling reduces. If not then we have a guide on bloat and dropsy in goldfish here which may help:
      dropsy/bloat in goldfish
      hope this helps

  8. Thank you so much for your post! I tried the epsom salt truck in my tank last night and this morning my poor medium size oranda had the thicker longest poop ever! Both fish that were swimming upside down are now right side up. I’ll float their food before feeding and also look for better food – I have koi pellets.

    • Hi Amy,

      we are happy to hear that the epsom salts worked for you, this is great news!
      Just make sure to do a water change after using them to remove the excess salt from the tank if you haven’t already.

      Koi pellets can come in a few forms, most pellets are very fiberous and filled with air, which can cause constipation for goldies.
      If the pellets are for growth, then they are very high protein, which can be hard to digest for goldfish.

      We recommend a mix of different foods, green beans from a can are an amazing food, they are cheap, easy to digest and prepare for fish, and are widely available.

      a good staple dry food are sinking goldfish pellets, algae wafers, and or herbivore cichlid pellets.

      two pellets we really recommend are the “tetra goldfish japan” sinking pellets, and the “vitalis herbivore” pellets.

      we also have a page full of feeding recommendations for goldfish here:

      hope this helps 🙂

  9. My goldfish seems to have a growth protruding from under a scale. I have been able to feel it. I’ve medicated him, Epsom salts etc. it just won’t go away. Any thoughts ?

  10. hello,i saved goldsfish form kids playground..he was laying on his side at the bottom of the tank,having hevavy breathing problems,his eyes were foggy and his fins staryed to rot.. i put a heater and uvb light in his hospital tank and i am giving him.antibiotics.. he became better..he isnt laying on his side anymore..his eyes are better looking..his apetite is massive..but he wants to eat a lot but not pooping..he bacem a little i am really woring right now.. what to do? he doesnt wanna eat peas.. do i continie to give him food or what? and yes i am giving him salt baths sometimes..


Leave a Comment