Guppy Fish Dropsy Disease, Symptoms and Remedies

Dropsy refers to a medical condition in both humans and aquarium fish when the belly becomes bloated due to accumulation of water or fluids in the guts and other internal organs.

What is Dropsy?

Dropsy disease in fish and guppies is not very common. Fish that has dropsy diseases have a bloated belly, really round, oval shape and its scales start to protrude, forming a pine cone appearance.

The bloat can be caused by fluid buildup in the colonic cavity, polycystic kidney disease, amoebae or bacterial infection (mycobacteriosis).

Many refer to dropsy disease as bloated or swollen belly diseases.

Can Guppy Fish Recover from Dropsy?

Dropsy caused by bacteria cannot be treated. It is contagious, but usually fish with strong immune system will not get infected.

Dropsy caused by other factors such as water pollution, stress or improper nutrition can be treated.

Dropsy Diseases Causes and Symptoms

As stated above, dropsy diseases in guppy fish and other fish can be caused by various factors.

Mycobacteriosis causes dropsy in very rare cases. Fish with strong immune system will not be affected by these bacteria. Though, if the immune system of the fish is compromised, it can lead to serious infections.

The immune system of fish can be weakened by various factors:

  • Poor water quality
  • Ammonia and nitrite spikes
  • Stress due to transportation or aggressive tank mates
  • Fluctuating water temperature
  • Improper feeding

Usually a small amount of stress will not affect the immune system in such a great manner, that fish will not be able to fight dropsy or other diseases. In most cases dropsy is and other guppy fish diseases are caused by water pollution.

How to Treat Dropsy?

If dropsy is caused by bacteria, the infection can affect the fish so quickly that it can’t be cured. Expert fish keepers recommend euthanizing and disposing the infected fish in order to stop the spread of the infection to other fish.

Others say that with proper treatment, some fish can be cured from dropsy. Here is a commonly recommended treatment for dropsy:

  • Quarantine the sick fish in a “hospital tank” (bare bottom tank with a sponge filter is best)
  • Once a day do an Epson salt bath in a separate container (2 tablespoon of Epson salt per gallon)
  • Feed the sick fish with fresh, high quality food (use good flake food)
  • Treat the hospital tank with antibiotics

It is important to quarantine the sick fish in order to prevent the spread of the disease to other healthy fish. Do a 50% water change on the original tank and monitor the remaining healthy fish in order to spot any early symptoms of dropsy.

You can treat the whole tank with Epson salt, however it is more effective to do short baths. Put one gallon of aquarium water in a separate container and add 2 tablespoon of Epson salt. Leave the fish in it for about 30-45 minutes. Put back the fish in the quarantine tank. Do this once a day.

Do not feed old fish food to your fish. If you have food that is older than 6 months, just get a new box of high quality flake food and feed that. You can also prepare fish food at home or feed live food. Make sure you feed a variety quality food to your guppies.

If the sick fish does not respond to the Epson salt treatment after a few days, you should use antibiotics. In most countries antibiotics can be prescribed only by a vet. By dosing antibiotics, you will also kill the beneficial bacteria in the filter. When treating your tank with antibiotics, test for ammonia and nitrites on daily basis.

How to Prevent Dropsy?

As I always say, it is much easier to prevent guppy disease than treating them. As with most other disease, dropsy is caused by poor water quality, wrong feeding, dirty fish tank, stress and lack of nutrients.

Here are some tips on how to prevent dropsy in your guppy fish:

  • Do regular water changes (30% weekly)
  • Maintain tank regularly (clean filter, vacuum substrate)
  • Do not overcrowd your tank
  • Do not overfeed your fish
  • Do not feed old food to your fish
  • Feed a variety and quality food
  • Keep the water temperature stable with a heater
  • Avoid aggressive tank mates

If you feed various high nutrient food and maintain your tank regularly, keeping the water parameters stable, the chances of your guppies developing dropsy is very low.

Guppy Fish with Bloated / Swollen Belly

It is normal that female guppies have bloated or swollen belly, especially when they are about to give birth. If your female guppy still has swollen belly after dropping the fry, maybe she is constipated or it is possible to have dropsy.

In guppy males bloated belly is not normal. They can also become bloated due to constipation if they are overfed. However if the male guppy presents symptoms such as this on in the picture below, most likely it has dropsy.


Male Guppy Dropsy Disease (source)

Is Guppy Pregnant or Has Dropsy?

In guppies dropsy is a bit harder to identify, because females develop a huge rounded belly when they are pregnant. Though, after they give birth, their belly will become less bloated.

If the fish spine becomes deformed, the gills become pale or the scales start elevating from the body, your guppy fish has dropsy and you should treat it accordingly.

Is Dropsy Painful for Fish?

For years there is a huge debate around this topic in the science world: do fish actually feel pain. Recent studies shows, that fish actually feel pain. But is dropsy painful? There is no proof about dropsy to be painful for fish, but in humans edema (dropsy) can cause severe pain.

Is Dropsy Contagious to Other Fish?

Dropsy caused by bacterial infection is highly contagious and can pass to other fish too. Though, fish with a stronger immune system can have a natural protection against dropsy.

As mentioned before, you can prevent dropsy if you provide your fish with the right water parameters and a variety of high quality food.

Is Epson Salt Good for Treating Dropsy?

Some fish keepers report that Epson salt is beneficial in treating dropsy. Some say, that Epson salt will cure dropsy.

It is true, that Epson salt baths will help the fish to recover and can improve the condition of the fish; however, as mentioned before, dropsy caused by a bacterial infection cannot be treated. So, fish keepers who had success with Epson salt, most likely had no fish invested with mycobacteriosis.

Is Dropsy Contagious to Humans?

Humans can also have dropsy disease. In human medicine, this is called Edema. In humans, Edema manifests as accumulation of fluid under the skin, which can cause sever pain.

Fortunately, fish dropsy cannot be passed to humans. Though, it is recommended to wear rubber gloves, when dealing or treating sick fish.

Should You Euthanize Fish with Dropsy?

If the fish presents advanced stage of dropsy disease such as protruded scales, you should euthanize it. There are few human ways you can euthanize guppies and other fish:

Anesthetic overdose: this can be done by a vet, because you can’t just buy anesthetic in a pharmacy. Usually the fish is placed in a smaller container with half gallon water. After adding the anesthetic, you should wait at least half an hour, because the overdosed anesthetic will not instantly kill the fish.

Clove oil: is a sedative which can be used to euthanize guppy fish. Mix up 1 gram of clove oil in 10-15 ml warm water. Place the fish in a small container with half gallon water. Add the clove oil mix to the container slowly. The fish need to stay in the solution for at least 15 minutes.

How to Verify Fish Death?

Whatever method is used to euthanize guppy fish, you should ensure that the fish is dead before disposal. A fish can be considered dead 10 minutes after the last gill movement.

The Takeaway

I hope this article has helped you learn about dropsy and how to treat it. Though, if you suspect your fish are sick, you should consult a vet as soon as possible.

If you have any questions, feel free to leave a comment below or send me an email.

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