13 Common Goldfish Diseases That Start Subtle But Turn Gross Fast

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If your goldfish looks lumpy, bloated, or like it’s growing fuzz, this isn’t just “a phase.” These common goldfish diseases can go from weird to deadly fast, and yes, I’ve got the freaky photos to prove it.

Whether it’s floating sideways or sprouting worms, here’s how to spot the signs and save your fish before it’s too late.

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Is My Goldfish Sick? 5 Red Flags

If your fish eats, swims, and usually acts, you have nothing to worry about. But if it’s ill, there are several warning signs to look out for.

Goldfish don’t cough, sneeze, or whine. They show sickness in weird, silent ways. Catching it early can literally save their life (and your whole tank).

Here are the top five warning signs your goldfish might be in trouble:

1. Floating Weird or Sinking Constantly

Look for: Tilting, tail-up posture, gasping at the surface

If your fish is stuck at the top, lying sideways, or sinking like a stone, it’s not being dramatic. Swim bladder issues, parasites, or organ failure could be behind it. Possible causes? Swim bladder disease, Dropsy, or internal infection.

2. White Fuzz, Film, or Cotton-Like Growths

Look for: Fuzzy white patches on fins, mouth, or body

Fungal infections or saddleback disease (columnaris) can make your goldfish look like it’s growing mold. It’s not normal, and it spreads fast. Possible causes? Fungal or bacterial infection.

3. Raised Scales That Look Like a Pinecone

Look for: Swollen belly, scales flaring outward, lethargy

If your fish’s scales are poking out all over like a pinecone, it’s likely Dropsy, and it’s serious. Possible causes? Dropsy (fluid retention and kidney failure).

4. Clamped Fins & Lethargy

Look for: Fins tight against body, low movement, dull color

If your goldfish has its fins stuck close to its body and just hovers, that’s a stress or sickness signal. Possible causes? Fluke, poor water quality, or infection.

5. Worms or Strings Hanging from the Body

Look for: Thread-like worms sticking out of the skin or tail base

It’s not poop, and it’s not normal. It’s probably an anchor worm, and yes, it’s as nasty as it sounds. Possible causes? Parasites (anchorworm or lice).

13 Goldfish Diseases: Images & Treatment

Not sure what that lump, fuzz, or fin damage means? These goldfish illness pictures and descriptions will help you identify what’s actually wrong, fast.

Whether your fish is bloated, pale, or sprouting something that looks like a fungus ball, scroll through this list to compare symptoms and study the goldfish disease images so you know what to do next.

1. Dropsy

What it looks like: A swollen belly and scales that stick out like tiny spikes, giving the fish a puffed, pinecone-like appearance.

Dropsy is not the full name of the disease. In today’s society, Dropsy is commonly referred to as Ascites, a collection of fluid in the internal organs. Dropsy is often caused by an accumulation of waste from the kidneys.

Dropsy isn’t the actual disease. However, a common symptom of Dropsy is belly swelling; others include skin lesions, pale color, bulging eyes, pale feces, and more. If you see a swollen belly, there is a 90% chance of kidney failure.

Ascites is a goldfish bacterial infection that occurs only when the fish’s body is stressed or weakened. The fish may float awkwardly, hover near the bottom, or lose interest in food. If untreated, Dropsy is often fatal.

Poor water quality, with spikes in ammonia and nitrites, among other issues, can cause this illness in your goldfish tank.

If your goldfish has already developed Dropsy, you can start their treatment by putting them in an isolated tank. It doesn’t need to be well-equipped, with the only essential needs being the primary filters and aerators.

After that, you should start giving your goldfish high-quality food. Try antibiotics like minocycline. I recommend API Melafix for Dropsy. Add a small amount of aquarium freshwater salt or plain Epsom salt to the water. 

2. Fin Rot

What it looks like: Frayed, torn, or blackened fin edges that appear to be dissolving.

Fin rot is one of the most common goldfish diseases caused by bacterial infections. It attacks the fins and, if left untreated, can cause the complete disappearance of fins and the eventual death of the fish.

Fin rot is a bacterial infection made worse by dirty water or stress. It often starts small, just a rough edge here or there, but quickly escalates.

The bacteria that cause this goldfish disease are always present in the aquarium. However, improper feeding of your goldfish or poor water conditions can cause the bacteria to become active. Another reason that activates this bacteria is long periods of cold temperature in the aquarium.

The best treatment for this goldfish disease is moving the infected fish into a bath of non-iodized salt. The concentration should be no more than two teaspoons per gallon. After the bath, trim the damaged part of the fin with a razor blade or a pair of scissors.

Alternatively, use a bath that contains 250 milligrams of Tetracycline per gallon for a week. After a whole day in this solution, let the fish rest in a mild salt bath. After that, treat with antibacterial meds like Fritz Maracyn, and monitor for signs of regrowth.

3. Anchor Worm

What it looks like: Thin, white or red thread-like worms sticking out from the fish’s skin, often surrounded by red, irritated patches.

Anchor worms got their names after the shape of their head. They burrow their heads into the fish’s bodies and feed on their blood. Anchor worm is not a disease. Instead, it’s a goldfish parasite commonly located near the pectoral or dorsal fin.

The most common way for your goldfish to get an anchor worm is from another fish. To prevent an infection from spreading throughout the entire tank, inspect the new fish carefully before adding it to the tank and quarantine it before introducing the fresh fish.

The easiest way to combat these parasites in a goldfish tank is to pick them off with a pair of tweezers. However, be careful if the worm is next to the fish’s eye. After the treatment, place the fish into a small, mild salt bath to combat any infections in the new wounds.

After placing them in a bath, you can treat the aquarium with parasitic treatment, such as Microbe-Lift Lice and Anchor Worm treatment. It will kill the remaining parasites, but their eggs will survive. Therefore, you’ll need to complete the treatment after another seven days to kill off all the eggs.

4. Fish Lice

What it looks like: Tiny, round, dark spots that move across the fish’s skin, usually only visible up close or under bright light.

Goldfish lice, which are actually crustaceans, can reach 3-4 mm in length when fully grown. They’re translucent and hard to see without a microscope. Their heavy infestation is a common goldfish disease. If not treated properly, it can lead to massive blood loss and even death.

Lice can get into the aquarium with new fish you introduce to your tank. However, plants and other objects brought from the wild and put into the aquarium without proper sterilization can lead to a fish lice infestation.

The most common sign of an infestation is when you see your fish rubbing themselves against any available objects in the tank. Such behavior can lead to missing scales and injuring the fish’s fins. You need to transfer the affected fish to another aquarium while you sterilize the water.

While the pesticide is doing its work, you need to kill all the parasites that stay on your fish using a parasitic treatment like Microbe-Lift Lice and Anchor Worm treatment. After that, put your goldfish into a quick salt bath, and then they’ll be ready for their home aquarium.

5. Fungus

What it looks like: Fluffy, white patches that resemble cotton balls growing on the body, fins, or mouth.

Fungus disease is one of the most common goldfish diseases. Fungal infections often occur after injuries, other illnesses, or inadequate tank hygiene. While they may look soft, fungal outbreaks can grow fast and kill slowly.

Fungus usually appears on the body or fins, and its appearance represents a patch of white cotton wool. If you don’t treat your fish, the fungus will spread from the skin to the muscle and then to their internal organs. An untreated fungal infection can be lethal to your fish.

In order to treat fungus, bathe your fish in a solution of non-iodized salt. However, if your fish is fragile, first add the fish to a weak solution.

After the treatment is completed, feed the fish live food to help it recover faster. To prevent this common goldfish disease, it is essential to keep the fish well-fed and maintain high water quality in the tank.

Treat the infection quickly with antifungal medications like API Primafix, and keep the water clean and pristine. These infections thrive in murky, unfiltered tanks.

6. Ulcers

What it looks like: Red, raw, crater-like wounds on the skin, often with inflamed or white edges.

Ulcers are caused by bacterial infections that breach the skin’s protective barrier. They’re painful, stressful, and dangerous, often leading to sepsis if ignored.

Usually, Ulcers come in tandem with parasites that penetrate the skin and provide the bacteria with plenty of flesh to work with. Watch closely as ulcers can deepen in just a day or two.

Ulcers can be diagnosed by their appearance. They resemble an open sore, with a pink/red color. Do not confuse it with gill ulceration, a condition that is part of a family of fungal diseases. An ulcer can be fatal to a fish if left untreated for an extended period.

Before treatment, ensure that the fish are free from parasites. After that, it’s essential to understand that ulcer treatment comes in three phases. First, you need to buy a hydrogen peroxide solution and treat the ulcer with a cotton bud.

After removing all the dead material, put the fish in a salt bath to kill all the remaining parasites and prevent fungal attacks. When you are finished with the salt bath, pick up some API Melafix, Malachite green, Methylene blue, oxytetracycline, or any other antibacterial medication that can be added to the water.

To prevent ulcers, consistently monitor the quality of the water. If your water quality is high, feed your fish regularly with live and frozen food and take care of their general health. This will prevent any parasite or ulcer infection.

7. Cloudy Eye

What it looks like: One or both eyes appear milky, hazy, or filmy, often with reduced movement or coordination.

Cloudy eye is a common disease in tropical fish and goldfish. It attacks the fish’s eyes and balance. It has various causes, from internal parasites to mechanical damage to the eye and poor water quality.

Fish infected with this disease often lose their sight and can even be seen swimming upside down due to the lack of coordination. However, the most notable symptom is a thin white film covering the entire eye.

To clear up a cloudy eye, you should take several steps. First, make sure the fish is not infected with bacteria or internal parasites. Cloudy vision is one of the most common diseases in goldfish and often occurs in conjunction with other conditions.

With that in mind, the first thing you should do is treat other diseases before treating the cloudy eye. Start by testing water parameters, especially ammonia and nitrites, and correct immediately. Use antibacterial support meds if signs persist. With fast action, this symptom is often reversible.

To prevent this disease, you must improve or maintain good water quality, remove all the sharp objects that can hurt the eyes of your goldfish, and ensure a healthy diet.

8. Carp Pox

What it looks like: Smooth, pale lumps on the skin or fins that look like melted candle wax or scar tissue.

Carp pox is a viral infection, and although it may look alarming, it’s usually harmless. These waxy bumps tend to appear in cooler water and may go away when temperatures rise.

Although Carp Pox is not a life-threatening disease, it should not be ignored. Like other infectious diseases, Carp Pox can be spread by introducing new fish that are added to your goldfish tank.

The most common signs of Carp Pox are the thickening of the epidermis on the fins and the traditional candle wax lesions. However, other infections can show the same symptoms, so your veterinarian’s further examination will help identify the disease.

There is no treatment for Carp Pox. Nevertheless, you can slow down the infection by strengthening your fish’s immune system. The best way to do that is by keeping a high temperature in your aquarium, giving high-quality food, and treating your fish with all the medications required.

9. Neurofibroma

What it looks like: Rounded, fleshy lumps that slowly form on the body, fins, or even the head.

Neurofibromas are tumor-like growths caused by abnormal cell development. They aren’t contagious and are usually benign, meaning they won’t spread to other fish or rapidly kill the one affected.

Still, they can interfere with swimming, feeding, or balance if they grow too large. There’s no real cure, but maintaining pristine water and reducing stress can slow progression.

In rare cases, an aquatic vet may surgically remove them, though most goldfish can live with neurofibromas for years. There is also a treatment that uses medication. However, it is not recommended due to its low success rate and possibly harmful side effects.

The cause of the occurrence of Neurofibroma, like any tumor, is due to the overexpression and replication of a cell. However, instead of killing the rogue cell, the fish’s natural defense allows it to replicate. Therefore, the tumor is formed in the fish’s skin or fin.

Unfortunately, there is no way to prevent a tumor in your goldfish. Neurofibroma is a genetic goldfish disease. However, maintaining good water quality and a balanced diet are good starting points for preventing infections.

10. Fluke

What it looks like: Excessive scratching, clamped fins, heavy breathing, and sometimes visible tiny worms on the gills.

Flukes are microscopic parasites that attach to the skin or gills, feeding on the fish’s tissue. They spread easily in crowded tanks and are one of the most common, yet often overlooked, hidden killers of goldfish.

You can usually tell if your goldie has Fluke if you see that it is scratching its back against the glass, has rapid breathing, and has mucus on the gills and body. Also, their skin may turn red, and their bellies may become sunken.

If untreated, Fluke can cause ulcers, secondary infections, and death. Treatment usually involves praziquantel (PraziPro), such as Hikari Prazi-Pro, or formalin-based medications. Always clean and treat the entire tank, since these parasites spread quickly to other fish.

The hardest part of Fluke treatment is making the correct diagnosis. Without a microscope, Flukes are practically undetectable. Therefore, you must eliminate the other most common goldfish diseases for your Fluke treatment to succeed.

However, if you are sure your goldfish has Fluke, disconnect the biological filters of your fish tank. You must kill all the parasites in the tank and the fish. Repeat this procedure until you are sure that the fish’s skin and gill are clean.

11. Ich (White Spot Disease)

What it looks like: Tiny white dots sprinkled across the fins and body, almost like salt or sugar crystals.

Ich is caused by a parasite that burrows into the skin and gills. Infected goldfish often rub against surfaces, breathe heavily, and stop eating. It spreads rapidly in tanks with poor water quality or temperature swings.

Treat with a combination of heat adjustment and anti-parasitic medication that targets Ich, such as Hikari Ich-X. Always treat the whole tank, not just the visibly sick fish.

12. Gold Dust Velvet

What it looks like: A fine, rusty-gold or yellowish dust coating the fish’s body, usually only visible under bright light.

Velvet is a parasitic infection caused by Oodinium, and it’s sneaky, and often mistaken for dirt or poor lighting until the fish starts clamping fins, flashing against objects, or showing rapid breathing. It spreads quickly in cold or poorly maintained tanks and can be deadly if ignored.

Treatment usually involves raising the water temperature and using a copper-based anti-parasitic medication, such as Seachem’s Cupramine. The earlier it’s caught, the better the survival rate.

13. Saddleback Disease

What it looks like: A pale or red band across the back, often between the head and dorsal fin, resembling a “saddle” shape.

Saddleback disease is caused by a bacterial infection, often columnaris, that attacks the skin and muscles along the back. The lesion starts as a light patch and can quickly become raw and ulcerated.

Infected goldfish may also show frayed fins, ulcers, lethargy, and loss of appetite. This condition spreads fast in poor water conditions and can be fatal if untreated.

Immediate action with antibiotics like oxytetracycline, including API Melafix, combined with salt baths and improved water quality, gives the best chance of recovery.

Quick Tip: Save or screenshot these goldfish disease images so you can compare them when something looks off. A quick photo match can often diagnose the issue faster than guessing, and might just save your fish’s life.

Want to Keep Your Goldfish Happy & Healthy? Don’t just stop at diseases – prevention starts with proper care! Check out our full goldfish care guide for more tips on feeding, cleaning, and tank setup.

Goldfish Disease Treatment: 6 Fast Steps to Save Your Fish

Once you’ve spotted the symptoms, the next step is to act quickly. Most common goldfish diseases can be treated if you catch them early. Here’s your step-by-step playbook.

1. Quarantine the Sick Fish

What it looks like: A smaller, separate tank with clean, conditioned water.

Moving your goldfish into isolation prevents the spread of parasites or bacteria to healthy tankmates. A bare-bottom tank with an air stone and heater is the most effective setup.

2. Improve Water Quality Immediately

What it looks like: Clear, stable water with zero ammonia or nitrites.

Most diseases are triggered by stress caused by contaminated water. Test the water parameters immediately with a water test kit such as the API Water Test Kit, and follow the instructions. Stable, clean conditions give your fish a fighting chance before meds even begin.

3. Use Aquarium Salt

What it looks like: White crystals dissolved in the water (non-iodized, aquarium-grade).

Salt helps reduce stress, promotes healing, and fights off mild infections. The general rule is to add one tablespoon per three gallons for supportive care; however, always research exact dosages based on your specific setup.

I recommend API’s Aquarium Salt for freshwater fish.

4. Apply Targeted Medication

What it looks like: Disease-specific treatments: antibacterial, antifungal, or antiparasitic.

Whatever the goldfish disease, the key is matching the treatment to the cause. Compare symptoms with images of goldfish diseases, then use targeted medications. Antibiotics for bacteria, antifungals for fuzz, and antiparasitics for worms or lice.

5. Support with Diet & Oxygen

What it looks like: Light feeding with easy-to-digest foods, plus boosted aeration.

Offer peeled peas for constipation or high-quality pellets. Increase oxygen with an air stone, as many meds reduce available oxygen in the water.

6. Monitor for 7–10 Days

What it looks like: Close observation of behavior, appetite, and wound healing.

Most goldfish will show improvement within a week if the treatment is working. If symptoms worsen, reassess: some conditions may need vet intervention or stronger medication.

Quick Tip: Don’t rush to medicate without checking the basics. Many “mystery” illnesses improve with better water quality and the addition of salt. Save heavy meds for when you’re sure of the diagnosis.

Can Other Fish Catch It? What You Need to Know About Contagion

A sick goldfish rarely suffers alone. Many common goldfish diseases spread quickly in shared water, which means one infected fish can put your entire tank at risk. Knowing which illnesses are contagious and how to stop them is critical.

1. Bacterial Infections

Common culprits: Fin rot, ulcers, cloudy eye.

These bacteria are already present in most aquariums, but they become active when fish are stressed. Once one fish shows symptoms, others are often exposed. Clean water and antibiotics in a hospital tank are the best defenses.

2. Fungal Infections

Common culprits: Cotton-like fuzz on fins, mouth, or wounds.

Fungus thrives in dirty or damaged tissue and can jump between fish. It spreads fast, especially if multiple fish have injuries. Treat both the sick fish and the environment with antifungal medication.

3. Parasites

Common culprits: Worms, lice, flukes, or flashing (scratching) behavior.

Parasites are highly contagious. Flukes and lice spread invisibly until every fish shows symptoms. Always treat the entire tank, not just the visibly sick fish.

4. Viral Infections

Common culprits: Carp pox, lymphocystis.

The good news: most viral infections aren’t easily spread between fish, and many are harmless. They can, however, reappear under stress. There’s no cure, just supportive care and clean water.

Quick Tip: If one goldfish looks sick, assume they’ve all been exposed. Quarantine sick fish, while also treating or monitoring the main tank. Prevention, such as access to clean water, stable conditions, and regular health checks, is the most effective way to prevent contagious outbreaks before they spread.

Goldfish Quarantine Tank: 5 Must-Haves

Every goldfish owner should have a quarantine setup ready. A simple hospital tank makes treatment easier, protects healthy fish, and often saves lives. You don’t need a fancy setup, just the basics.

1. The Tank

Best choice: A small, bare-bottom aquarium, 10–20 gallons, is suitable for most goldfish.

Select a simple glass or plastic tank without gravel or decorative elements. Bare bottoms make it easier to spot waste, parasites, and changes in behavior. Watch this short video showing how to set up a hospital tank.

2. The Filter & Aeration

Best setup: A sponge filter connected to an air pump.

Sponge filters are cheap, safe for sick fish, and provide gentle circulation. Add an air stone to maintain high oxygen levels, which is especially important when using medications that reduce oxygen in the water.

3. The Heater

Why it matters: A small, adjustable aquarium heater (if your home gets cold).

A stable temperature reduces stress and helps medications work properly. Goldfish are cold-water fish, but sudden drops below 65°F can worsen disease.

Check out our guide on the best water heater for small tanks, or discover how good in-line aquarium heaters are. And don’t forget a heat controller to help you maintain the ideal tank conditions.

4. The Water

Key detail: Fresh, conditioned water with no ammonia or nitrites.

Test your water before filling the quarantine tank. Use a reliable water conditioner, such as TankFirst Aquarium Water Conditioner to neutralize chlorine, and perform partial changes every 1–2 days during treatment.

5. The Essentials Kit

What to keep on hand:

• Aquarium salt (for stress and mild infections)
• A net used only for the hospital tank (to avoid cross-contamination)
• A siphon or turkey baster for quick clean-ups
• Medications matched to the illness (antibacterial, antifungal, or antiparasitic)

Quick Tip: Don’t overcomplicate it. A quarantine tank doesn’t need plants, décor, or gravel; it just requires clean water, aeration, and the right medication. Simple setups are easier to clean, making treatments far more effective.

How to Prevent Goldfish Diseases Before They Start

Preventing disease isn’t about expensive equipment; it’s about small habits that keep your tank stable and your fish stress-free. Think of this as your goldfish health insurance.

1. Test Water Before It’s a Problem

Prevention hack: Use an aquarium test kit weekly

Most illnesses appear after water quality deteriorates. Regularly testing for ammonia, nitrites, and nitrates helps you identify and address issues before they harm your fish.

Once your tank is set up, regular cleaning is just as important, as it can keep many common goldfish diseases at bay.

2. Don’t Buy Trouble at the Store

Prevention hack: Quarantine new fish, plants, and even décor

Many outbreaks start with new arrivals carrying parasites or bacteria. A two-week quarantine in a spare tank is the most cost-effective prevention step you can take.

3. Treat Food Like Medicine

Prevention hack: Rotate high-quality pellets with fresh peas or leafy greens

Goldfish are prone to digestive issues that mimic disease. A varied diet keeps their gut healthy and prevents constipation-related problems.

Choose a high-quality fish food with fresh vegetables, since balanced nutrition supports their immune system and helps fight off illness before it starts.

4. Give Them Space to Breathe

Prevention hack: Stick to 20 gallons for the first fish, plus 10 per additional fish

Overcrowding causes stress, increases waste levels, and facilitates the spread of parasites. More water means fewer diseases.

A goldfish’s health starts with the right environment, so investing in a properly sized goldfish tank, at least 20 gallons for one fish, with 10 extra gallons per additional fish, gives them room to grow and keeps waste from building up to disease-causing levels.

5. Know What Healthy Looks Like

Prevention hack: Compare your fish against goldfish illness pictures

Catching subtle changes early is easier when you know what “normal” looks like. Take your own reference photos of your fish when they’re healthy, as it makes spotting trouble simple.

Quick Tip: Think long-term: prevention is about forming habits, not relying on one-time fixes. Stable tanks, good food, and quarantine practices will protect your fish from the most common goldfish diseases before they ever appear.

What Are the Signs of a Dying Goldfish?

When a goldfish is nearing the end of its life, its body and behavior begin to shut down. These signs are serious and often mean your fish is suffering. Watch for these common signs:

• Floating sideways or upside down for long periods
• Lying at the bottom of the tank, unresponsive
• Loss of appetite, won’t eat even favorite foods
• Gasping at the surface or rapid breathing
• Dull or greyed-out color; fading or patchy scales
• Clamped fins held tightly against the body
• Sunken eyes or a bloated belly
• Open sores or ulcers that won’t heal

If you notice these symptoms, move the fish to a quiet, clean quarantine tank, add aeration and aquarium salt to reduce stress, and treat with broad-spectrum medication if the symptoms persist or are unclear.

Follow all the guidelines above and consult a veterinarian if the above steps don’t help. Some fish decline slowly, others crash fast. If you see multiple signs and treatments haven’t worked, it may be time to consider humane euthanasia.

FAQs: Goldfish Disease Treatment

Got questions about sick goldfish? You’re not alone; these are the ones goldfish keepers ask most often. I’ve answered them below, but if your question isn’t here, drop it in the comments and we’ll find the answer for you. Your question might help another fish owner save their pet, too.

How Can I Tell If My Goldfish Is Sick?

What it looks like: Clamped fins, faded color, loss of appetite, or floating oddly. Some fish develop visible issues like fuzz, lumps, or ulcers.

If your fish looks “off,” trust your instincts. Compare it against goldfish illness pictures to narrow down the problem. Early isolation and water testing are the best first steps before starting any goldfish disease treatment.

What Are the Best Treatments for Goldfish Diseases?

Most illnesses respond to three basics: quarantine the sick fish in a separate tank, add aquarium salt to reduce stress and fight infection, and use targeted medication (antibacterial, antifungal, or antiparasitic).

Water quality is critical, and many common goldfish diseases start with dirty or unstable tank conditions. Clean water is often the most powerful cure.

Are Goldfish Diseases Contagious?

Yes, many are. Parasites like Fluke, Anchor worm, and Ich spread through the water, while bacterial and fungal infections can jump quickly between fish.

That’s why one sick fish can turn into a tank-wide problem if ignored. Always treat the whole system, not just the visible patient.

When Should I Euthanize My Goldfish?

If your goldfish is unable to swim, refuses all food, or shows advanced symptoms like sunken eyes or severe ulcers, it may be time to consider humane euthanasia. Speak to your vet, who can advise you on the best course of action.

What’s The Difference Between “Goldfish Diseases” and “Goldfish Deseases”?

Nothing, except spelling. Many people search for “goldfish deseases” by mistake, so you’ll see that version online. The conditions are the same: Dropsy, fin rot, ulcers, parasites, and more. This guide uses both spellings to help anyone searching find the right answers.

Why Is My Goldfish Floating Weird?

What it looks like: The fish may drift on its side, belly-up, or struggle to stay upright. Odd swimming is often linked to swim bladder issues, constipation, or infections like Dropsy. Sometimes it’s temporary, caused by overfeeding, but persistent floating problems are a serious warning sign.

Try fasting your fish for a day, then feed a pea to relieve constipation. If symptoms continue, check for other common goldfish diseases and be ready to isolate the fish for treatment.

Learn More About Goldfish

Share Your Goldfish Story! Think your goldfish might have one of these diseases? Drop a comment with what symptoms you’ve seen or share the weirdest thing your fish has ever done. Your experience might help another goldfish owner save their pet (and yes, we love funny tank stories too).