• Bacterial Fin Rot

• Pop-eye

• Cloudy Eye

• Bacterial External Infections, Fish Turberculosis skin infecttion, Columaris

• Fish Turbeculosis systemic infection

• Dropsy

• Hemorrhagic Septicemia

• Swim bladder disease

Common Name:  Bacterial Fin Rot

Pathogen/Cause: Various organisms (nonspecific)

Physical Signs: Shredded-looking and tattered fins decreasing in length, sometimes infected down to the pedicle.

Behavioral Signs: Increasing difficulty swimming, behavioral signs depend on whether other secondary infections present.

Potential Treatment: Broad spectrum antibiotics.

Other Notes: Frequent water changes a must to improve quality. Test for ammonia, nitrites, nitrates.

Common Name:  Pop-Eye

Pathogen/Cause: Various organisms (nonspecific), Severe Stress

Physical Signs: Exopthalmos (protrusion of the eyeball from the socket) caused by accumulation of pus and fluid in the infected orbit.

Behavioral Signs: Associated with loss of vision, also just general signs of lethargy.

Potential Treatment: Broad spectrum antibiotics. Many formulations available. For a more thorough discussion on the various causes & treatments of popeye, please refer to Dan's archived comments about popeye.

Other Notes: Frequent water changes a must to improve quality. Test for ammonia, nitrites, nitrates. Pop-eye is a sign of a number of infections, rather than a disease in its own right. For more on this disease, read this.

Common Name:  Cloudy Eye

Pathogen/Cause: Various organisms (nonspecific), Severe Stress, Malnutrition, Cataracts, Old Age, Hyperproduction of slime due to poisoning, bad water quality, or irritation.

Physical Signs: A cloudy white or grey "haze" over the eyes that may cause blindness.

Behavioral Signs: Associated with loss of vision, also just general signs of lethargy.

Potential Treatment: Investigate if water quality is high first (water changes), then if nutritional needs of that species are being met. Wait at least a week or two before trying any antibiotics, it will often clear on its own if water quality is high.

Other Notes: Frequent water changes a must to improve quality. Test for ammonia, nitrites, nitrates. Cloudy eye is a sign of a number of things, rather than a disease in its own right.

Common Name:  Bacterial External Infections, Columnaris (specific to F. columnaris); Often Misnamed "Mouth Fungus", Fish Tuberculosis/TB Skin Infection (specific to Mycobacterium spp.)

Pathogen/Cause: Various organisms. Positive diagnosis not possible outside of lab culture & microscopy (not practical for most hobbyists). Gram positive: exceedingly rare in FW fish; small handful of SW species, but most primarily do not attack skin. Gram negative: Flexibacter columnaris, Aeromonas spp., Pseudomonas spp., Vibrio spp., Salmonella spp., many others not listed. Non-stainable: Mycobacterium spp., mostly M. piscium & M. marinum

Physical Signs: White, clear, red/pink areas of necrosis. Occasionally slightly ragged/fuzzy appearence. Inflammed patches and sometimes deeper ulcers develop. Various patterns of appearence and presentation. Columnaris usually presents near the head and sides of the body and is often mistaken for a fungus; it is characteristically white and patchy.

Behavioral Signs: Various: lethargy, hiding behavior, "hanging", clamped fins, loss of appetite, general constitutional signs.

Potential Treatment: Broad spectrum antibiotics. (Examples include but are not limited to: Maracyn I & II, Jungle Binox, Aquatronics Kanacyn, etc.). Frequent water changes a must to improve quality. Tuberculosis is difficult to treat because it attacks intracellularly.

Other Notes: Frequent water changes a must to improve quality. Test for ammonia, nitrites, nitrates. Columnaris perhaps one of the most common skin infections of pet fish (livebearer fish and certain other fish especially susceptible). Specifically for F. columnaris, read this article by Dr. Barb. Fish tuberculosis (though not transmitted by the same species that causes human tuberculosis) can be transmitted as zoonosis called "fish tank granuloma" on hands with open wounds (again, another article by Dr. Barb discusses this issue. Use gloves if reaching in the tank with suspect animals.

Common Name:  Fish Tuberculosis/TB Systemic Infection

Pathogen/Cause: Mycobacterium spp., mostly M. piscium & M. marinum.

Physical Signs: Various presentations, hard to make certain diagnosis without necrospy or lab culture. Includes: wasting away, shrunken stomachs, occasionally skin infections, spinal curvature deformity in advanced cases.

Behavioral Signs: Various: anorexia/refusal to eat, lethargy, hiding behavior, "hanging", clamped fins, loss of appetite, general constitutional signs.

Potential Treatment: Difficult to treat because it attacks intracellularly and multiplies within macrophages (the fish's own defense system). Try a strong antibiotic such as kanamycin sulfate or streptomycin. Euthanasia must be considered in bad cases.

Other Notes: Fish tuberculosis (though not transmitted by the same species that causes human tuberculosis) can be transmitted as zoonosis called "fish tank granuloma" on hands with open wounds (see photos, below). Use gloves if reaching in the tank with suspect animals. M. marinum can be a serious skin infection in people! If a rash such as this developes, especially if you have a marine aquarium, make sure your hobby is known to your doctor. Read this article for more info.

Common Name:  Dropsy

Pathogen/Cause: Various organisms (nonspecific), poor water quality.

Physical Signs: Bloated appearence with scales that stick out like a pine cone. Best viewed from above. Dropsy is not really a specific pathologic entity, it is to describe a general condition of fluid accumulation in the internal body cavity, which has many causes. Dropsy usually signals internal infection and multiple organ failure. It can be compared to ascites in humans in end stage kidney failure.

Behavioral Signs: Lethargy, lack of appetite, grave constitutional signs.

Potential Treatment: Unfortunately, dropsy is *usually* incurable and fatal; however, in rare cases, spontaneous recovery may occur. A strong antibiotic such as kanamycin sulfate can be tried, but because it is an internal infection, usually it does little good.

Other Notes: Take measures to improve water quality immediately. Fortunately, it is not highly contagious.

Common Name:  Hemorrhagic Septicemia

Pathogen/Cause: Various organisms, Ammonia spike

Physical Signs: Distinct bright red streaks on fins (caused by vascular inflammation due to systemic/bloodborne bacterial infection) and occasionally patchy red discoloration on the flanks of the body.

Behavioral Signs: Depends on severity of condition. If due to ammonia, may show in conjunction with hyperventilation (fast breathing) and gasping at the surface, erratic swimming, etc.

Potential Treatment: Broad spectrum antibiotic. Can resolve spontaneously in some fish if source of water quality problem is removed.

Other Notes: ChecK water quality, especially if fish exhibiting other signs of ammonia poisoning (gasping at surface). Regular water changes and measuring of ammonia/nitrite (especially if relatively new tank) are a must. In FW, commonly seen in goldfish due to their naturally high ammonia output. In SW, often seen in tangs due to their inability to tolerate sudden water quality changes and susceptibility to shock.

Common Name:  Swim Bladder Disease

Pathogen/Cause: Various; Often indigestion in goldfish and other "balloon" breed fish, but may be bacterial infection in other species. Occasionally, sudden trauma such as when fish are jostled excessively in transit or "dumped" into water without acclimatization may result in fatal injury to the swim bladder.

Physical Signs: May show some limited bloat, but usually no real physical changes.

Behavioral Signs: Fish has great swimming upright despite active attempts to do so. May occasionally float "belly up".

Potential Treatment: Different depending on species; goldfish are very susceptible and sometimes cured by discontinuation of diet and salt bath, followed by change in diet to high fiber digestible foods. However, other fish may require antibiotics and have a worse prognosis. Recently introduced fish that exhibited signs within a matter of minutes have the worst prognosis of all, and there is often no cure for trauma to the swim bladder.

Other Notes: Most common in "pot-belly" shaped breeds of fish, such as goldfish & parrot cichlids due to blockage and insufficient fiber/vegetable matter in the diet. However, many fish that suffer trauma or excess stress, or just get an internal bacterial infection that occurs on or around the swim bladder may have problems. Baby fish fry that have swim bladder problems are commonly known as "belly sliders" (most scoot around the bottom fo the tank, unable to swim up, or spin uncontrollably in the water). It is still unknown if this is the same exact disease entity or what the cause is, but most attribute it to congenital or developmental causes, sometimes birth defects, premature birth or inadequate nutrition at certain stages. They should be culled to prevent suffering.