Fish Disease Checker

Velvet is caused by the dinoflagellate parasite Oodinium and creates a fine gold or rust-colored dusting on the fish's skin. It is often mistaken for a color change and can be harder to spot than Ich. Extremely contagious and fatal if untreated, especially in Bettas.

Dropsy is not a single disease but a symptom of severe internal bacterial infection causing fluid accumulation in body tissues and organs. The fish swells dramatically and scales protrude outward like a pinecone. It has a high mortality rate and requires immediate aggressive treatment.

Columnaris is a bacterial disease caused by Flavobacterium columnare that mimics a fungal infection with white or gray cotton-like patches. It commonly appears on the mouth, body, and along the dorsal (back) area. Very contagious and fast-progressing — fish can die within 24-48 hours of visible symptoms.

Hemorrhagic Septicemia is a serious systemic bacterial infection (Aeromonas hydrophila) causing internal and external bleeding. It is often triggered by stress, overcrowding, or poor water quality. The disease progresses rapidly and has high mortality if not treated within the first day of symptoms.

Bacterial Gill Disease is a bacterial infection targeting the gills, causing them to swell, fuse, and become coated with mucus. The gills lose their ability to extract oxygen, leading to suffocation. Common in crowded tanks with poor water quality and in fish recently subjected to stress.

Ich is one of the most common freshwater fish diseases, caused by the parasite Ichthyophthirius multifiliis. It appears as tiny white spots resembling salt grains on the fish's body and fins. Highly contagious and can wipe out an entire tank if left untreated.

Popeye is characterized by one or both eyes protruding abnormally from the head due to fluid accumulation behind the eye. It is usually caused by bacterial infection, injury, or poor water quality. While the condition itself can be treated, severe cases may result in permanent eye damage or loss.

Anchor Worm is a crustacean parasite (Lernaea) that physically attaches itself under the fish's scales, with a visible Y-shaped or thread-like body hanging from the skin. Common in pond fish and goldfish imported from outdoor ponds. The attachment point becomes inflamed and secondary infections can develop.

Fish Lice are flat, disc-shaped crustacean parasites (Argulus species) that attach to the skin and feed on blood and tissue. They are visible to the naked eye as greenish or brownish oval discs on the body. They cause intense irritation and can transmit secondary diseases at bite sites.

Gill Flukes are microscopic flatworm parasites that attach to the gills with hooks, causing intense irritation and damage to gill tissue. They are very common in imported fish and pond fish. A light infestation may go unnoticed but heavy infections cause respiratory distress and secondary bacterial infections.

Body Flukes are related to Gill Flukes but attach to the skin and fins rather than the gills. They are live-bearing and can rapidly multiply on a single host fish. Infestations cause intense irritation, skin damage, and create entry points for bacterial and fungal secondary infections.

Cotton Mouth is a bacterial infection primarily affecting the mouth area, creating white cottony or fuzzy growths around the lips and jaw. Similar in appearance to Columnaris, it causes the mouth to deteriorate making it impossible for the fish to eat. Most common in Bettas and tetras under stress.

Fin Rot is a bacterial infection (commonly Aeromonas or Pseudomonas) that causes the fins and tail to deteriorate and fray. It is usually triggered by poor water quality, stress, or injury. Caught early it is very treatable, but advanced cases can reach the body and become fatal.

Swim bladder disorder causes a fish to lose its ability to control buoyancy, resulting in sinking, floating upside down, or swimming sideways. It can be caused by overfeeding, constipation, bacterial infection, or physical injury. Goldfish and Bettas are particularly prone to this condition.

Hole-in-the-Head is a chronic disease most commonly seen in Flowerhorn, Cichlids, and Discus. It creates small pits and erosions on the head and along the lateral line. Caused by Hexamita parasites, nutritional deficiencies, or poor activated carbon water quality. Slowly progressive but manageable.

Saprolegnia is a common water mold that appears as white or gray cotton-wool patches on the body, fins, or around wounds. It typically attacks injured or immunocompromised fish and is often a secondary infection following injury or bacterial disease. It spreads rapidly in cold water.

Various internal worm parasites including Camallanus, tapeworms, and roundworms can infect aquarium fish. Fish with internal worms often look healthy initially but gradually waste away despite normal feeding. Camallanus worms may be visible as red thread-like worms protruding from the vent.

Wasting Disease, often called Guppy Disease or Microsporidia infection, causes progressive muscle wasting in livebearing fish — especially Guppies. The fish's spine curves and the body bends into a characteristic C-shape or S-shape. Caused by Microsporidian parasites and is generally incurable but containable.