Badman's note. Pandora an old
friend of the site is currently unable to further her work and her former
webhost is on a temporary Hiatus. Working with her former host and friend
I was able to recreate much of Pandoras hard work and once again offer
most of this valuable resource to all hobbyist. I cleaned up the tables
some and removed any broken links, all text is original.
Disease
Most of the time, troubleshooting by frequent water changes and avoiding
fish stress will prevent serious outbreaks of disease in the tank. Off
the list of preventative things, I cannot stress buying small numbers
of fish SLOWLY enough; many a tank can be devastated by bringing in a
large number of new fish in a relatively small time. Healthy fish can
actually cohabitate with some disease organisms at low concentration without
becoming symptomatic, but when fish are stressed by sudden environmental
changes and overcrowded conditions, their immune systems don't function
well and they become far more susceptible to disease. New fish especially
are vulnerable, because they have been passed from breeder to wholesaler
to distributor to retailer to consumer and most likely spent the whole
time in horrid surroundings. They should be quarantined in a separate
tank whenever possible.
Some diseases can be tenacious once they take hold in a tank. Be sure
to try and figure out a general diagnosis before dumping a lot of medication
into the tank, as some meds are toxic dyes that can kill with overdosing
(especially to sensitive fish such as tetras and scaleless cats), and
some, such as antibiotics, will wreak havoc on your biofiltration and
throw your established tank into a new cycle. Keep in mind that "sometimes
the cure can be worse than the disease" (and ALL chemical additions
to the tank which change water conditions stress the life inside the closed
environment). Also, keep in mind that most plants and inverts will not
tolerate many medications in the water. In planted aquaria, it is best
to remove the affected fish to the quarantine tank or into a small treatment
vessel with circulation and heat. It is sometimes helpful to add a small
(1tbsp/5gal) amount of aquarium salt (NOT marine salt, which is different),
as most medications disturb healthy gill function, and the salt reduces
osmotic shock and electrolyte loss... but this is a somewhat controversial
issue that I address in the following article (pros & cons): To
Salt or Not to Salt?.
I've been working on a photo archive of fish diseases
that people send me or allow me to use from their sites. This list and
archive of photos is not meant to be exhaustive or comprehensive. Please
note also that some diseases have multiple manifestations (Columnaris,
NTD, Fish TB, to name a few), and may vary in presentation from fish
to fish; others are not true "diseases" caused by a single
organism, but rather signs that could point to a number of causative
organisms (dropsy, pop-eye). Click on the thumbnails, and you will be
linked to the larger photos (if it was larger to begin with, that is,
I can't enlarge photos any larger than they were when sent to me, because
this will not improve resolution).
THIS IS AN ONGOING PROJECT THAT IS ALWAYS BEING ADDED
TO. IF YOU HAVE A RELATIVELY CLEAR PHOTO OF A FISH WITH A DISEASE THAT
YOU THINK I CAN USE, PLEASE EMAIL ME.
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FUNGAL INFECTIONS
Common Name: |
Body Fungus |
Pathogen/Cause: |
Saprolegnia spp. |
Physical Signs: |
A very fuzzy growth which projects from
the skin or fins of the fish. Usually has the "fluffy" appearence
of food molds, can be white or grey. Needs to be differentiated from
"false mouth fungus" Columnaris (see above). True parasitic
fungus prefers to grow on already dead tissue and will often coexist
with bacterial infections. |
Behavioral Signs: |
Usually not severely affected until later
stages. |
Potential Treatment: |
Many formulations available, including
brand names: Jungle Fungus Guard, Mardel Maroxy, Aquarium Pharmaceuticals
Fungus Cure and generic formulations usually containing methylene blue. |
Other Notes: |
Fungal infections are relatively rare but
do happen in already weakened fish. They will be very distinct in appearence,
as opposed to Columnaris, which is probably far more commonly seen in
the aquarium (less protrusion of fibers, just a ragged fuzzy appearence).
See photos to differentiate. |
Photos:

Courtesy of Chuck's Pets & Hobbies
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Courtesy of Pet Care Forum
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Common Name: |
Cotton Fin Fungus |
Pathogen/Cause: |
Various, often Saprolegnia spp. |
Physical Signs: |
Cotton-like "fluffy" or wispy
growth trailing on fins of fish. Can gradually promote decay of tissue. |
Behavioral Signs: |
Usually not severely affected until later
stages. |
Potential Treatment: |
Many formulations available, including
brand names: Jungle Fungus Guard, Mardel Maroxy, Aquarium Pharmaceuticals
Fungus Cure and generic formulations usually containing methylene blue. |
Other Notes: |
Prefers to attack already damaged or injured
tissue. Most important action is to do water changes and increase circulation
of the system. Saprolegnia prefers to live in stagnant water.
Sometimes improvement of water quality alone will erradicate the disease. |
Photos:

Courtesy of Jungle
Labs |
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Courtesy of Michele Hartley
(very bad case of fungal infection on caudal fin; likely secondary to
erosion by primary bacterial infection) |
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VIRAL INFECTIONS/TUMORS
Common Name: |
Lymphocystis, Cauliflower Disease |
Pathogen/Cause: |
Lymphocystis spp. (A DNA Iridovirus). |
Physical Signs: |
Viral infection that causes cells to
become megaloblastic, thus forming small tumors (bumps or growths),
often along the lateral line or the pedicle, where the fin meets
the body. The tumors sometimes take on the appearence of tiny cauliflowers,
thus the name. |
Behavioral Signs: |
Lethargy, general symptoms, may affect
balance and swimming control if along the lateral line. |
Potential Treatment: |
Frequent water changes and reduction
of ammonia and nitrites in water may reduce stress to help the fish
battle the infection and shrink tumors on its own. Interestingly,
cyprinids & catfish which have been studied appear to be resistant. |
Other Notes: |
Watch for secondary bacterial infections. Often attacks
large fish fed with live foods. Cichlids are especially susceptible.
Please check World
Cichlid's page on HITH/HLLE which has much more detailed info,
theories, and potential treatments of this disease. Also, Dr.
Barb's Flippers and Fins Site has some more info for curious
minds. |
Photos:
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My own photo (Taken at a local pet store which
will remain unnamed.)
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Courtesy of Tom Choi
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Common Name: |
Solid tumors of unknown cause |
Pathogen/Cause: |
Not fully understood in fish or man.
Many oncoviruses may be suspect in turning off genes involved in
tumor suppression. In fish, just as in other animals, may be benign
or malignant (cancerous). |
Physical Signs: |
Growing mass of tissue, can occur on
almost any part of the body. |
Behavioral Signs: |
Usually not overtly affected unless
the tumor is very fast growing internally, or obscures vision, feeding,
or swimming. |
Potential Treatment: |
None for most fish. Seek veterinary
help for large and/or expensive fish. Surgery often the only cure,
though rarely will shrink back on its own. |
Other Notes: |
Not much known about the fish oncology
at this time. Watch tumor closely for fast, uneven growth of tumor.
If it keeps the fish from feeding and/or swimming, consider euthanasia. |
Photos:

Courtesy of The Welborn Pet Hospital.
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Courtesy of Joel Rose
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Courtesy of Mike Hottovy
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EXTERNAL ARTHROPOD PARASITES
Common Name: |
Anchor Worm |
Pathogen/Cause: |
Lernea spp. |
Physical Signs: |
Actually, lernea is a copepod (crustacean
arthropod) rather than a true worm. It looks like a small whip (a
few mm to under an inch long) attached to the fish at the mouth
end and with a forked tail. |
Behavioral Signs: |
Usually none noted unless very severe
with secondary infections. |
Potential Treatment: |
May be physically removed, but will
cause great stress to the animal, and must be done carefully and
with a dab of antibiotic over the wound afterwards. Brand name formulations
like Jungle Parasite Guard and Aquarium Pharmaceuticals may also
help. |
Other Notes: |
Rarely seen in pet fish not kept outdoors
(in ponds), and usually then only in ones that have been fed live
foods. |
Photos:

Courtesy of The Dept. of Western Australian
Fisheries
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Courtesy of Qian Hu Inc.
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Courtesy of "JJ"
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Courtesy of John Childers (this photo is one
of the best high-resolution photos I've ever seen of its kind; really
captures the anatomy of this parasite in detail)
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Common Name: |
Fish Louse |
Pathogen/Cause: |
Argulus spp. |
Physical Signs: |
A flat disk-shaped arthropod parasite
with many legs. On the fish itself it is barely noticeable only
as a flat, dull colored bump that you may just think is a part of
the fish, unless you see the legs themselves or the disk moving
around on the body. |
Behavioral Signs: |
Usually none noted unless very severe
with secondary infections. |
Potential Treatment: |
May be physically removed, but will
cause great stress to the animal, and must be done carefully and
with a dab of antibiotic over the wound afterwards. Brand name formulations
like Jungle Parasite Guard and Aquarium Pharmaceuticals may also
help. |
Other Notes: |
Rarely seen in pet fish not kept outdoors
(in ponds), and usually then only in ones that have been fed live
foods. Crustacean not related to true lice, which are insects. |
Photos:

Courtesy of Niklas
Gustavsson
(beautifully clear image of fish louse out of water!)
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Courtesy of Qian Hu Inc.
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Courtesy of The Aquatic Animal Health Research Institute
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TRUE WORM PARASITES (TREMATODES,
NEMATODES, CESTODES)
Common Name: |
Flukes (Skin, Gill, or Eye) |
Pathogen/Cause: |
Dactylogyrus vastator (Gill
Fluke), Gyrodactylus sp. (Mostly Skin Flukes), etc. |
Physical Signs: |
Gill flukes may show with red, inflamed
gills, but otherwise many fish flukes are microscopic (some of the
largest being just a few mm, but mostly smaller), and so confirmed
diagnosis by physical appearence alone is not possible. Confirm
with a vet or lab. |
Behavioral Signs: |
Scratching, gasping at surface (again
a nonspecific sign that has other more common causes, see comments
at right). |
Potential Treatment: |
A good, thorough discussion of treatment
options can be found in Dan's
archived comments on fluke treatment. |
Other Notes: |
No photos are included here, because usually
flukes are too small to visualize with the naked eye. This also
creates serious problems for trying to diagnose by general physical
signs (hyperproduction of slime, inflamed gills) or general behavioral
signs (listlessness, gasping, scratching, etc.). All these signs
overlap considerably with other more common causes of skin and gill
irritation, including ammonia poisoning and more common skin parasitisms
such as ich. The first step in any tank where these signs are seen
is to rule out ammonia poisoning first by testing for any level
above 0. |
Photos:

Courtesy of Cindy
Buors (blurry photo of worm-like parasite on gill; large for
most gill flukes, which are difficult to see with the naked eye;
may possibly be another type of external parasite)
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Click photo |
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Common Name: |
Roundworms |
Pathogen/Cause: |
Unknown nematode species (metacercarean
form) |
Physical Signs: |
As shown below as an infection of connective
tissue (usually internal worm infections cannot be seen externally and
often affect the gut; in these cases, they have migrated to muscle tissue). |
Behavioral Signs: |
Loss of appetite, lethargy, etc. |
Potential Treatment: |
Try Clout or an antiparastic medication
for large parasites (formalin and many methods were tried on the
first cases below without success). There is also some good information
on the
treatment of camallanus worms as contributed by Jason Parry. |
Other Notes: |
Please read my article, Worms in my tank??
before jumping to the conclusion that any worm in the tank is a
parasitic or disease causing worm. The large majority of small worms
seen in the aquarium not attached to the fish are free-living and
harmless (the ones shown below are an obvious exception). Most of
these true parasites shown below require a fish host at some time
in their life cycle. They often come in with contaminated live foods
such as Tubifex worms. |
Photos:

Courtesy of Mike Spafford
(unknown/possible sparganosis of nematode infection attacking muscular
tissue)
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Courtesy of Mike Spafford
(unknown/possible sparganosis of nematode infection attacking muscular
tissue)
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Courtesy of Tom Lorenz
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Courtesy of Kevin Piper (another unpleasant photo of camallanus worms protruding from
a fish)
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Courtesy of Averi Dohr
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Courtesy of Anonymous (an interesting photo sent
to me; moving nematode was found between the scales of a large koi)
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MISCELLANEOUS AILMENTS
Common Name: |
NA / Unidentified Lesions, Growths & Cysts |
Pathogen/Cause: |
Unknown--those shown below could have a
number of causes--they could be bacterial infections that formed
pus-filled cysts under the skin, they could be true tumors (see
above), Lymphocystis, cysts that formed around worms, etc.
Because I was uncertain, I didn't want to mislabel them, so I keep
them here in the hopes that they will still help someone, if they
see something similar. For a more thorough discussion of various
causative organisms, please refer to Dan's
archived comments on "unknown lumps & bumps". |
Physical Signs: |
Varies greatly. |
Behavioral Signs: |
Varies greatly. May have no affect on behavior
at all, depending on cause. If near the mouth and it hinders eating,
could have obviously faster consequences. |
Potential Treatment: |
Unknown, may be incurable in some (if they
turn out to be true tumors); depends on individual case. For those
exuding pus and fluid and/or those cases where behavioral lethargy
and malaise is seen, try an antibiotic. More detailed information
on different treatment options that can be attempted can be found
in Dan's
archived comments on "unknown lumps & bumps". |
Other Notes: |
These pictures shown below may span a wide
range of different causes. Some are clearer than others. |
Photos:

Courtesy of Mike Spafford
(case shown above is recurrent; suspect lympho, but without certainty)
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Courtesy of Yew Wee Tan (this didn't look like any classic "textbook
presentation" of anything that I knew of, except possibly a clumping
bacterial or fungal nidus on the trailing caudal fins; photo clarity
didn't permit me to say for sure... if anyone has any idea of this being
more specifically characteristic of something else, please let me know)
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Courtesy of Michele Hartley (beautiful photo of a true hollow
cyst; I believe that it may have originated with a bacterial infection
just under the skin, and then grown enormously due to pus accumulation;
fish shown above died within a relatively short time of first
appearence)
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Courtesy of Luigino Bracci (amazingly clear photos
of such a small, darting fish; it is beyond my knowledge what this growth
could be, it was described to me as an adherant circumscribed and object
that the owner believed may have been a parasite; however, it is larger
than and distinct from most of the common fish parasites I am aware
of) |
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Courtesy of Nick
Austin(beautiful series of 3 professional-quality photos; appear
to identify the same multiloculated, fluid-filled cyst)
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OTHER
Photos:
Courtesy of Michele Hartley
(illustrates fight injury in male bettas that jumped barrier)
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Courtesy of Michele Hartley
(illustrates fight injury in male bettas that jumped barrier)
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Courtesy of Kamphol (shows a normal gravid loach [the equivilent of "pregnant" for
egglayers]--obviously not a disease state, used here only for the purposes
of comparison with pathologic causes of bloating)
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Courtesy of Nathan Cantrell (superficial skin injury secondary to trauma; likely at this
point not yet seriously infected, but may be in a subacute time frame)
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