Signs Of A Constipated Goldfish: Treatment and Care Guide

goldfish swimming in tank
Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: July 7, 2024
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Have you ever seen a goldfish swimming upside down? Did you notice its belly had grown or that it was moving unusually slowly?

These are all signs that your once-healthy goldfish may be having serious digestive issues, which can mean constipation or potential illness.

Treating constipation in goldfish can be a complicated process, as it can stem from a variety of causes.

If you’ve ever seen the symptoms of a constipated goldfish and wondered what to do, read on for how to determine the exact cause and treat it.

Article Summary

  • Constipation can be life-threatening for goldfish if left untreated, leading to toxic buildup and potentially fatal consequences.
  • Factors contributing to goldfish constipation include diet, overfeeding, lack of exercise, swim bladder disease, and cold water temperature.
  • Treatment options for constipated goldfish include consulting a veterinarian, improving water quality, feeding peas to aid digestion, and using Epsom salt baths.

What is Goldfish Constipation?

Much as people on the surface, constipation in goldfish and other fish species means that they are unable to process or pass feces through their digestive tract. This can be incredibly painful if untreated, and leads to a wealth of other problems down the road.


Goldfish metabolism plays a critical role in how easily your fish’s body is able to digest and pass food. Older fish, or those already suffering an illness will have a lowered metabolism and a harder time passing food through their digestive tract.

Constipation in goldfish can be caused by several different factors, including diseases affecting the digestive system such as fatty liver or fin rot, overfeeding, or the goldfish’s diet being unbalanced.

goldfish appearing to be smiling
Remember to keep your goldfish healthy and happy!

The key to determining just what is going on and treating constipation comes down to isolating which factors are off in your particular tank.

Can Goldfish Die Of Constipation?

If you are unable to treat your fish for constipation and change your feeding to reflect this, your sick goldfish may indeed die.

As with other animals, not being able to pass feces can cause a buildup of toxic waste inside of their body as they feed, leading to deadly toxic shock or sepsis.

… not being able to pass feces can cause a buildup of toxic waste

With proper treatment and feeding, your fish should return to normal within the course of as little as a day after passing waste.

How Long Can a Goldfish Remain Constipated?

Given that it can be hard to determine exactly when in your normal feeding schedule that your fish has started the process of constipation, it can be difficult to answer this question.

If you continue to feed as per usual and food continues to accumulate in their system, the constipation can begin to wreak havoc on the normal bodily functions of your goldfish in as little as a few days.

When it comes to fatality, it may take between a few days and weeks for constipation to reach a lethal level and poison your fish.

That being said, if your constipated goldfish is already being fed an inadequate diet and water parameters in your aquarium are off, that process can be expedited.

Signs of Goldfish Constipation

There are several important signs and symptoms to look out for when trying to notice constipation in your fish.

Girl looking at an aquarium
Make sure to constantly pay attention to your fish

While most of these are somewhat more obvious in nature, it is up to the aquarium owner to know the normal behavior and feeding patterns of their goldfish.

Stringy Feces/Long Poop

This is actually a sign that your fish has not been feeding regularly.

While some may think that something is wrong with the food inside of their fish, this is an indication that the bowel movement does not contain any actual food.

a fish excreting feces
Make sure to take note when your fish relieves itself (1)

Not to mention, if your fish is able to pass stringy feces or long poop in the first place, it is likely not suffering from constipation. You may see this as a white coloration or in the color of the pellets that you typically feed your goldfish or fancy goldfish, and it’s a part of regular life for a fish to pass poo this way.

Not Passing Stool

While it may be hard to notice unless you are able to monitor the bowel movement of your goldfish fairly consistently, not passing stool at all is essentially the definition of constipation.

Fish suffering from constipation will be unable to pass any sort of material until they have been treated and are able to properly digest their meals again

No Appetite

Lack of desire to eat can be a major problem for your fish. Noticing after a day or two that they do not eat any food may be a sign that constipation is the culprit.

Lack of desire to eat can be a major problem for your fish.

However while this can be one of the symptoms of constipation it there are many other illnesses, diseases, and issues that could be the case in what exactly is affecting your fishes.

In some instances, having your goldfish stop eating is less a result of constipation and more of a sign that they have had enough food and need more time to digest.

Constipation in goldfish can be a tricky thing to diagnose on one’s own and it is best left to a professional.

Bloated Belly

The term dropsy comes from an old English medical term for swelling in the abdomen caused by gasses or fluids. The “drop” refers to the way the belly of the fish appears to droop in appearance as it swells.

underside of a bloated goldfish
A goldfish whose belly appears bloated (2)

Today it would more likely be referred to as an edema, but either way it can lead to serious health complications in goldfish.

Signs of a Goldfish With Dropsy

Swelling around the eyes, bloated belly or stomach, the presence of lesions, scale loss, or abrasions, and becoming lethargic, constipation, or acting excessively tired and swimming in irregular ways

Dropsy is caused by a group of several bacteria commonly present in most home freshwater aquariums.

An unstressed, healthy fish can handle the presence of these bacteria without much problem. Unfortunately, by the time the more serious symptoms of dropsy begin to manifest it may be too late.

Treatment for Belly Bloat

Treatment for bloat can be difficult and require medications or the use of aquarium salt, but a good place to start is by removing the afflicted fish to a separate tank to prevent dropsy from spreading.

Erratic Swimming

Swimming in an unusual manner (upside down, exclusively on the bottom, or at the top of the tank) may be a sign of constipation in goldfish.

Additionally, this can indicate that a number of things may be wrong with your goldfish, from issues with the swim bladder, to parasitic infection.

Constipation may not be the immediate cause, but if you notice that your goldfish is swimming oddly in addition to not having passed waste for some time constipation may be to blame.


A constipated goldfish will likely exhibit symptoms of lethargy, swimming around slowly or not at all as its body attempts to pass undigested waste.

two goldfish sleeping under an aquarium decoration
Also try to note where they sleep or rest (3)

Noticing a gold fish moving sluggishly or residing at the bottom of the tank, it could also indicate that the water in your aquarium is too cold, or that they have in fact not had enough food and may be tired or sluggish as a result.

Swim Bladder Disease

Seeing a goldfish having trouble swimming can be a sign that something is wrong with their swim bladder.

Your goldfish swimming upside down, moving awkwardly, or being unable to move are all signs that something may be off with the air bladder of your goldfish, which is meant to control their movements throughout the water column.

What Causes Constipation In Goldfish?

There are several distinct possible culprits that can lead to constipation in gold fish.

Some of these are harder to detect, such as disease, while others such as providing a balanced and varied diet may be much easier to treat for the home aquarium.


Goldfish are omnivores, meaning that they require a balanced intake of both proteins, dietary fiber and plant-based nutrients.

Ensuring that your goldfish’s diet is well balanced and provides them with the right set of fiber and nutrition is the best way to prevent constipation in goldfish. Aside from proper diet and dietary fibers, adding brine shrimp to your goldfish diet can help.


In a pinch, you may notice your goldfish eating the plants in your aquarium to try to get more fiber and nutrition. While there are live plants that can handle a few goldfish nibbles, some plants are sensitive and may not survive a goldfish bite.

Checking in with your veterinarian of choice, along with the pet store or breeder from which you initially purchase can provide great guidance on their diet and just what you should be feeding your goldfish to prevent constipation.

Many stores sell specially-formulated foods specifically for goldfish, which contain the balance of vitamins and minerals, and dietary fiber that they would be otherwise unable to get.


Looking at the ingredients for most formulated fish foods will show you that they’ve got about the same amount of fiber as peas, around 5%. The reason for this is because goldfish digestive systems aren’t meant to digest too much dietary fiber at one time, seeing as they wouldn’t consume peas or fibrous vegetables often in the wild.


Feeding your fishes too much food can lead to a blockage in their digestive tract, causing constipation. Even with the dietary fiber from pellets or plants, overfeeding can wind up with your goldfish becoming constipated.

fish coming up to ead pellets
Make sure you give your goldfish just enough food!

Remember that your goldfish will typically feed as much as it can in a given session and plan to feed them only as much as they need.


Even if your goldfish aren’t overeating and becoming constipated as a result, having excess pellets or flakes can cause the tank water to become contaminated. A good rule of thumb is to remove uneaten food within a half an hour of feeding in order to prevent excess ammonia buildup which can potentially poison your goldfish if left unchecked.

Allowing your goldfish the proper amount of time to pass the extra food that they have consumed may help if they can end the constipation on their own.

However in some extreme circumstances if symptoms progress, they may need surgery in order to remove the blockage and become un-constipated.

Lacking Exercise

Given that we cannot necessarily encourage our fish to exercise regularly, an unhealthy or unfit goldfish can be hard to treat.

If you notice that your goldfish tends towards sloth, perhaps consider adding in more interesting decorations, slightly increasing the water flow of your filter, or adding air bubbles in your goldfish aquarium system to encourage them to move more and get the food moving through their system to ease constipation.

Also, if you currently house your goldfish in a pet bowl, consider upgrading to a larger aquarium to give them more space to swim or explore. Smaller space results in limited movement for your goldfish.

Swim Bladder Disease

The swim bladder is the air filled organ in a goldfish that allows for movement throughout the tank.

When your fish gets swim bladder disease, this air becomes either too concentrated or may dissipate causing buoyancy problems, leading it to either sit on the bottom, float awkwardly around, or your goldfish swimming awkwardly in the tank.

goldfish coming up to the water
Make sure you observe how your fish are swimming

Swim bladder problems can be incredibly difficult to deal with for the fish itself, as they’ll have difficulty eating and reaching their food.

A swim bladder issue can quickly change from simple bladder issues into malnourishment and further illness if not properly treated.

Swim Bladder Treatment

To resolve swim bladder issues, consult your veterinarian or local pet shop if there are serious symptoms such as trouble breathing or being unable to swim altogether to determine which swim bladder disease medication is right for your fish.

A good first step in controlling swim bladder disorder is to move the sick fish to a quiet, isolated tank so that it is not further stressed and can’t introduce illness to fish in the tank.

The Water Is Too Cold

As the water temperature decreases, so too does the metabolism of your fish which can lead to constipation in your goldfish at drastic levels.

Goldfish are a cold water fish that prefer temps between 50 and 60 degrees Fahrenheit, and lowering the water temperature below this can alter goldfish metabolism, causing their metabolism to slow down and hindering the capability of these cold water fish to properly digest food.


If you notice that your tank temperature has become too low, consider the use of a heater to ensure that your goldfish does not become constipated as their digestive system slows.

What Should You Do If Your Goldfish is Constipated?

If you find that your goldfish has become constipated, a good first step is to consult with a veterinarian. They will be able to properly diagnose the symptoms affecting your goldfish and causing the constipation, so that they can help you treat it.

In any case, this helpful video will give you an idea of what to do if you notice your goldfish is constipated.

Treating constipation in goldfish


As with many goldfish issues such as constipation, consider removing them to a separate quarantine tank. This will allow your goldfish to recover from constipation in isolation and avoid spreading whatever potential illness or bacteria may be causing it to other goldfish tank mates.

Check the conditions within your tank, and think back to how you normally feed your goldfish to determine if something has changed recently that may be causing the constipation. Changes in diet or poor water quality can be the likely culprit.

Make sure that you do not stop giving meals to your fish! If they do not actually have constipation, refusing to provide food to your goldfish will only make matters worse. But don’t give your fish more food than usual either.

How To Treat Constipated Goldfish

There are a few guidelines for treating a constipated goldfish. In general, working on the water quality in your tank should be the priority.

If your fish is suffering from some unknown illness, performing frequent water changes of 10-25% and cleaning the tank’s filtration system to improve poor water quality will be much more effective than simply having them eat green peas, brine shrimp, or using epsom salt.


Adding tinned peas or shelled peas to your fish’s diet can help aid with digestion. Peas provide a relatively small amount of fiber to the diet, but can ease the symptoms of a constipated goldfish.

Peas generally act as a mild laxative, and if you feed a pea to your constipated goldfish it may provide just enough fiber to help symptoms pass.

Should you choose to add tinned peas to their diet, consider starting small with one pea at a time to ensure that they will actually eat them. Adding more peas than they’ll eat at any one time can simply add to the problem!

Epsom Salt

Along with a balanced diet, a good technique in your goldfish first aid kit, the use of salt to aid in fighting off constipation is a good one.

Epsom salt in a bowl
Epsom salt is a great thing to have in a pinch

While referred to as an “epsom salt bath,” this technique is more used to assist the entire tank with ammonia poisoning or disease control, along with the symptoms of constipation.

When we refer to aquarium salt, we typically think of table salt, or NaCl. While this may be more readily available, it isn’t the best choice for our home aquarium as it often contains iodine and anti-caking components that can make it potentially harmful for your goldfish.


As epsom salts can act as a natural laxative for your goldfish, an epsom salt bath can be a good way to help them pass any undigested materials or green peas out of their system and end constipation.

Therefore we recommend epsom salt baths as a safe way to help fight off infections and diseases such as dropsy, along with aiding your constipated goldfish.


Throughout today’s article, we’ve looked at the effects of constipation in goldfish, its causes, as well as some potential ways to treat it.

The key factors are providing a varied diet for your goldfish and monitoring your tank as a whole, so that you know how conditions are and prevent poor water quality along with regular partial water changes to keep things fresh in your tank.

Identifying symptoms can be the greatest challenge in helping your goldfish return to its healthy self.

Feel Free To Share!

As always thank you for reading this post, I hope that it has helped answer all of your goldfish constipation questions.

Feel free to share this info with other fish fanatics you may know and I wish you the best of luck on your continued aquarium adventures!

(1) Poop Time by Klaus Stiefel – licensed under CC BY-NC 2.0
(2) OMG! by Jill Siegrist – licensed under CC BY-NC-SA 2.0
(3) sleeping goldfish by Jelene Morris – licensed under CC BY 2.0

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