🐟Fish Health

Fish Health Guides

19 guides on fish health, cited to the veterinary literature — symptoms, conditions, and when to see a vet.

Most pet-fish illness starts with water quality, so buoyancy problems, clamped fins, or sudden lethargy are often the first sign the tank chemistry is off. These guides cover common goldfish and aquarium-fish concerns and help you tell a husbandry fix from disease that needs an aquatic vet.

🐟Fish HealthAug 15, 2026

🚨Emergency

Goldfish Gas Bubble Disease: Signs, Causes, and Urgent Steps

Tiny bubbles in a goldfish's fins, eyes, or tissues can signal dissolved-gas supersaturation. Learn how this differs from ordinary popeye or buoyancy trouble and what to check now.

🐟Fish HealthAug 13, 2026

🌿Skin & Coat

Goldfish Fin Rot: Signs, Causes, and What to Do First

Ragged goldfish fins can come from injury, poor water conditions, or bacterial disease. Learn what progression looks like, what to test today, and when fin damage needs an aquatic veterinarian.

🐟Fish HealthAug 12, 2026

🚨Emergency

Goldfish Ammonia Poisoning: Signs, Test Results, and First Steps

Ammonia poisoning can injure a goldfish before the water looks or smells unusual. Learn which signs matter, how pH and temperature change the meaning of an ammonia result, and what to do first.

🐟Fish HealthAug 11, 2026

🐛Parasites

Betta Ich (White Spot): Why the Spots Vanishing Doesn't Mean It's Over

Salt-grain white spots on a betta usually mean ich (Ichthyophthirius multifiliis). Only the free-swimming stage can be killed by medication, so treatment runs on a schedule — daily at 75°F–79°F, a minimum of 3 to 5 treatments — not until the spots vanish. Here is how to tell ich from velvet and columnaris, and what to do tonight.

🐟Fish HealthAug 8, 2026

🚨Emergency

Betta Dropsy: What Pineconing Scales Really Mean

Dropsy is not a disease you can cure with a bottle from the fish shop. It is the outward sign of fluid collecting inside a betta, often from a failing organ or a systemic infection. Here is what is really happening, what to test today, and what your options are.

🐟Fish HealthAug 6, 2026

🐛Parasites

Goldfish Flukes: Signs, Causes, and How They Are Diagnosed

Gill and skin flukes are microscopic worms that often appear after a new goldfish arrives. Learn what monogenean flukes are, why Dactylogyrus and Gyrodactylus behave differently, the signs owners notice, and why a scrape under a microscope is the only way to be sure.

🐟Fish HealthAug 2, 2026

🍽️Eating & Drinking

Goldfish Not Eating: Causes, Fixes, and When to Worry

When your goldfish stops eating, the water is usually the real story. Here's how to find the cause, water quality first, then temperature, stress, diet, and disease, with a simple step-by-step plan and the red flags that mean it's time to call an aquatic vet.

🐟Fish HealthJul 29, 2026

Velvet Disease in Betta Fish: Spotting and Treating the Gold-Dust Killer

Velvet is a fine gold-dust parasite that attacks a betta's gills first and spreads fast. Learn to spot it with a flashlight, tell it apart from ich, and treat it in the dark.

🐟Fish HealthJul 28, 2026

Columnaris in Betta Fish: The 'Cotton' Disease That Isn't Fungus

That white cottony fuzz on your betta's mouth or fins looks like fungus but is usually columnaris — a fast-moving bacterial disease that warm water makes worse. Here's how to recognize, treat, and prevent it.

🐟Fish HealthJul 27, 2026

🤮Digestive

Goldfish Constipation: Signs, Causes, and How to Help

A constipated goldfish trails stringy feces, bloats, and may start to float or sink. Here is how to spot it, gentle ways to help at home, and when a swollen belly signals something more serious.

🐟Fish HealthJul 26, 2026

👁️Eyes & Ears

Betta Popeye (Exophthalmia): Causes, Treatment, and Recovery

One or both of your betta's eyes suddenly bulging is popeye — a sign, not a disease on its own. Here's what causes it, why clean water is the real cure, and when to call an aquatic vet.

🐟Fish HealthJul 25, 2026

Betta Fish Fungus: White Fuzz, Cotton Mouth, and How to Treat It

White, cotton-like fuzz on a betta is usually one of two very different problems — true water-mold fungus (Saprolegnia) or columnaris, a bacterium that only looks fungal. Here's how to tell them apart, why the difference flips the treatment, and how to fix the water and temperature that let it start.

🐟Fish HealthJul 22, 2026

Goldfish Fungus: Cotton Wool Disease vs. Columnaris

The white cotton-wool fluff on a goldfish is usually one of two look-alike problems: Saprolegnia water mold (true fungus) or columnaris, a bacterium that only looks fungal. Here's how to tell them apart, fix the water first, and know when to call an aquatic vet.

🐟Fish HealthJul 21, 2026

Betta Swim Bladder Problems: Floating, Sinking, and Listing to One Side

Your betta is floating, sinking, or tipping sideways. "Swim bladder disease" is a sign, not a diagnosis — and bettas differ from goldfish in ways that change the fix. What to check first, what actually has veterinary backing, and when to call an aquatic vet.

🐟Fish HealthJul 18, 2026

Goldfish Dropsy: Why the "Pinecone" Look Is a Warning Sign, Not a Disease

Dropsy in goldfish isn't an illness you treat directly — it's fluid buildup that signals a serious internal problem. Here's how to recognize pineconing, tell it apart from bloating or a swim bladder issue, what to do first, and the honest prognosis.

🐟Fish HealthJul 17, 2026

🍽️Eating & Drinking

Betta Fish Not Eating? Causes and What to Do

A betta that skips meals is usually reacting to its water, not its food. Here are the most common reasons bettas stop eating — cold water, ammonia, overfeeding, stress, and illness — plus simple steps to get your fish eating again.

🐟Fish HealthJul 16, 2026

🐛Parasites

Goldfish Ich (White Spot Disease): How to Spot It and Treat It Safely

Ich, or white spot disease, is a common goldfish parasite that looks like grains of salt. Here's how to recognize it, why the life cycle dictates treatment, how to clear the whole tank, and when gill involvement becomes an emergency.

🐟Fish HealthJul 15, 2026

🌿Skin & Coat

Betta Fin Rot: Why It Happens and How to Heal Your Betta's Fins

Fin rot in bettas is almost always a sign of poor water quality, not bad luck. Here's how to spot it early, fix the tank first, and know when medication or an aquatic vet is needed.

🐟Fish HealthJul 14, 2026

🤮Digestive

Goldfish Swim Bladder Disorder: Why Your Fish Floats, Sinks, or Tips Over

If your goldfish is floating upside down, listing sideways, or stuck on the bottom, swim bladder disorder is usually a sign of a water-quality or feeding problem — not a single disease. Here's how to find the real cause, what to do first, and when to call an aquatic vet.

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