Guppy Dropsy 101 (Causes, Symptoms, Treatments and Prevention)

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Available in a range of vibrant colors, Guppies are tropical freshwater fishes that have become popular due to their playfulness and peaceful nature. 

However, they are pretty vulnerable to various diseases, dropsy being the most dangerous among them. Therefore, it’s essential to pay attention to their maintenance requirements. In this guide, we will tell you all about Guppy dropsy and how you can prevent it. 

So, without further ado, let’s get started. 

What Is Guppy Dropsy?

Dropsy is a disease that affects guppy fishes and is marked by hugely swollen, oval-shaped bellies. In this condition, their stomach becomes bloated, and their scales protrude due to water or fluid retention in the gut or other internal organs.

If not treated at the outset, it proves to be fatal for the fish.

What Causes Dropsy In Guppies?

A weakened immune system leads to Guppy dropsy. If the fish has low immunity levels, a bacterium called Aeromonas infects and eventually kills them. However, this bacterium is always present in most aquarium settings, and it is only when your Guppies’ immunity levels are compromised that this microorganism can infect them. 

Several factors can lead to a weakened immune response in Guppies. We have listed some of them below. 

Poor Water Quality

The presence of decaying plant matter, old food particles, and dirty gravel can reduce the water quality. Moreover, excess ammonia and nitrates in the tank can lead to a spike and, eventually, tank poisoning. 

Stress And Injury

Stress caused by hostile tank mates is one of the leading causes of dropsy in Guppies. In addition, an injury sustained because of transportation from one tank to another can also lead to this disease. 

Poor Nutrition

If you are not feeding your Guppies the food they need, their immune system will weaken over time, and they will become vulnerable to attacks by bacteria. This results in the development of dropsy syndrome. 

Fluctuating Water Temperatures

A significant drop or rise in water temperatures can disrupt the balance inside the tank. Fluctuating temperatures will adversely impact the body of your fish and lead to stress and “temperature shock.” If not corrected, it can damage their organs and lead to a weakened immune system response. 

How To Tell If My Guppy Has Dropsy?

The symptoms of dropsy are very prominent but vary widely. We have listed the most common ones below.  

Pinecone Scales

One of the definite signs of dropsy is the appearance of pinecone-like scales. Since the belly becomes swollen, the scales can no longer stick to the sides of the fish’s body and protrude. 

Swollen Stomach

The infection can lead to a distended or massively swollen belly. Often, it is easy to confuse a bloated stomach with constipation or swim bladder disease, so look out for other signs to confirm if it is dropsy. 

Curved Spine

The pressure inside the Guppy’s body is so severe due to swelling of the stomach that it can bend its spine. Sometimes, the spine swells in a vertical direction, and this is more likely because of tuberculosis. In dropsy, the spine curves in a horizontal form. 

Other signs of dropsy include:

  • Bulging eyes
  • Fins clamped by the side
  • Discolored gills
  • Lack of movement and low appetite 

How To Cure Dropsy In Guppies?

Although the mortality rate for Guppies suffering from dropsy is high, if diagnosed early, the condition can be treated. So, here are the different approaches you can take to cure dropsy in your fish.


The first step towards treating your Guppy is to transfer it to a separate tank to reduce stress and allow focused treatment. Besides, it prevents the spread of infection to other fishes in the tank. 

Don’t make the quarantine tank smaller than the recommended size for Guppies, which is 5 gallons. Also, transfer some water from its previous tank to the new one so that the good bacteria is transferred to the quarantine tank, and your fish will not have to get accustomed to different water parameters. 

Aquarium Salt Treatment

Once your Guppy has been transferred to the “hospital tank,” it is time for the salt treatment. There are specifically formulated aquarium salts, but some aquarists also recommend using Epsom salt. 

As a rule of thumb, you should add one teaspoon of salt for every gallon of water. However, remember not to add more than the recommended dose of salt, as an excess of it can further disrupt the osmotic balance of the Guppy. 

Focus On High-Quality Diet

Since dropsy is primarily a result of a weak immune system, you should focus on feeding a high-quality diet to your Guppy. We recommend a balanced diet full of blanched vegetables, live food, and flakes. In addition, you should remove any uneaten food from the tank without fail to avoid the buildup of ammonia. 

How Do You Prevent Dropsy In Guppies?

As the old saying goes, prevention is better than cure. This especially holds true for dropsy, which is pretty challenging to treat. So, you must take certain steps to prevent your Guppies from contracting this disease. These include:

Maintaining A Clean Tank

Change the water in the tank often, clean the filter, and use a heater to balance the temperature inside the tank. All of these steps will prevent a nitrate or ammonia spike and keep bacteria at bay. 

Avoid Overcrowding

Don’t overcrowd the tank with too many fishes as it results in a higher bio-load. Besides, do not place aggressive tank mates with your Guppy. 

Don’t Overfeed The Fish

It is essential to feed high-quality food to your fish but don’t make the mistake of overfeeding them as it can result in swim bladder disease and constipation. 

Since Guppies are omnivores, maintain a balance between plant-based and animal-based food products. 


Is Guppy Dropsy Contagious To Other Fish?

Usually, dropsy is not contagious if the other fishes in the tank have a strong immune system. However, it is still advisable to shift the affected Guppy to a separate tank. 

Can Guppy Fish Recover From Dropsy Naturally?

It is highly unlikely that your fish will be able to recover from dropsy naturally. You need to treat it with salt, antibiotics and keep it in a separate tank. Even then, if the disease has reached advanced stages, recovery is unlikely. 

Is Guppy Pregnant Or Has Dropsy?

Female guppies have swollen bellies while pregnant, but if the swelling doesn’t decrease even after dropping the guppy fry, then it might be suffering from dropsy. 

To verify if it is dropsy, look for other symptoms such as discolored gills, curved spine, etc. 

Is Dropsy Painful For Guppies?

No. There is no evidence of dropsy being painful for Guppies. 


We hope this article has given you a complete overview of Guppy dropsy. Unfortunately, although this disease is treatable, in some cases, euthanization becomes the only option. So, it is always better to take adequate preventive steps to keep this infection miles away from your Guppies. 

Here’s a quick bit of advice before we go. You don’t need a fancy tank for your Guppy, but make sure it is spacious enough since these fishes thrive in a larger space. Besides, always look for suitable tank mates. 

With that, we come to the end of this guide. If properly taken care of, your Guppy will remain healthy for years to come!

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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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