Why Does My Goldfish Look So Bloated?

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Goldfish are some of the most common pets, and they’re beautiful to look at as they swim around their tank. However, if you notice that your fish looks swollen in the abdominal area, you might wonder what’s causing the bloating and if it harms the fish.

Your goldfish looks so bloated either because you’re feeding it too much and it’s gained weight. It could also be because it’s carrying eggs or suffering from a condition called dropsy. There are various ways to treat and prevent dropsy in goldfish.

In this article, I’ll discuss some potential reasons for your goldfish looking bloated and what you can do to help solve this issue and prevent it in the future. Let’s get to it!

Reasons for Goldfish Bloating

If you notice your goldfish is looking a little bulkier than usual, especially in the abdominal area, there are a few potential causes for this issue:

You’re Overfeeding Your Goldfish

All animals are prone to gaining weight if they overeat, so you should only feed your goldfish the amount it can consume in under two minutes twice a day. Overfeeding can also cause indigestion and tank contamination.

If you think your goldfish looks bloated because you’re overfeeding it, the simple solution is to reduce how much you’re feeding it. Once you have the fish on a healthier diet, it will lose weight and look less bloated.

Your Goldfish Is Preparing To Lay Eggs

Your goldfish might appear bloated if it’s preparing to lay eggs. Of course, this is only the case if the goldfish is female, there is another fish present it could’ve bred with, or it is spring. In this case, it’s best to let nature take its course and look forward to some baby goldfish in the tank.

Your Goldfish Has Dropsy

Another more serious cause of goldfish bloating is dropsy. Dropsy can cause your goldfish to experience abdominal swelling, which is a result of another infection or parasite.

Dropsy is one of the most common conditions in freshwater fish, including goldfish. For more information about freshwater fish, check out my article on what kind of fish can live in a freshwater tank.

If dropsy infects your goldfish’s kidneys, it can cause them to retain water, making them unable to maintain a healthy fluid balance in their bodies. This issue can cause bloating so severe that the scales start to flip outwards, and in most cases, the fish will seem lethargic and unhappy.

Symptoms of Dropsy

Other symptoms of dropsy include the following:

Red fins
Bulging eyes
Paleness
Swollen anus

Stress can also mimic the symptoms of dropsy. Any amount of stress can cause the fish to start retaining water and bloating, and this stress can include the following situations:

Fungal infection
Parasite
Liver problems
Bacterial infection

If your fish has dropsy, you’ll need to correct the underlying problem to rectify it and reduce bloating. In this case, it’s worth consulting your vet.

How To Treat Dropsy

A goldfish with dropsy is not a good sign. However, there are some things you can do to treat the condition.

Here are my top suggestions:

Replace the water. Your fish will be happier in fresh, clean water, but avoid doing a massive water change. I recommend not doing more than a 50% water change. For more information, check out my article on “Can you change more than 50% of your aquarium water.”
Add a little bit of salt to the tank. Increasing the water salinity can be helpful for a fish’s osmotic balance.
Give your fish antibiotics. If your fish has a fungal or bacterial infection, it will likely need medication to return to health. Consult a veterinarian to see what they recommend.

The underlying condition causing dropsy isn’t always treatable, but it’s worth a try.

How To Prevent Dropsy

Unfortunately, in some cases, the underlying condition causing dropsy is too severe to undo once you’ve noticed the bloating. Often, goldfish exhibiting signs of dropsy end up dying shortly after.

Therefore, the best method is to avoid dropsy altogether. Here is some helpful advice:

Clean the tank regularly, including the filter.
Don’t overfeed your fish.
Avoid putting too many fish in one tank.
Change the tank’s water regularly.

Dropsy doesn’t necessarily guarantee goldfish death, but it isn’t a good sign. If you follow these tips, you can keep your goldfish as healthy as possible.

Final Thoughts

There are three main reasons why a goldfish might look bloated:

It’s overweight.
It’s about to lay eggs.
It has dropsy.

Dropsy is a condition in which the fish’s kidneys hold onto water, which causes abdominal swelling, and another underlying condition causes it. You can sometimes treat dropsy, but it is far better to prevent it altogether.