There will be times when no matter how much you
search, you won't be able to diagnose what is ailing your fish and you will
lose some. Just like all living creatures, illness and death sometimes
will remain a mystery with fish as well. All that any of us can do is attempt
to arm ourselves with as much information as possible to give our little
friends the best chance of enjoying a long happy life.
Ichthyopthirius Multifiliis (Ich) is caused by a protozoan. It has been
found that Ich can lie dormant at the base of fins on a healthy
fish until they are in a period of stress. The only time that the Ich is
susceptible to treatment is during the "free swimming stage" The
developed cyst will fall from the host fish and the cyst will then "hatch"
releasing hundreds if not thousands of new parasites free to infect other
fish. This disease is highly dependent on the temperature of the water
the fish are being kept in.
These parasitic flatworms will appear as tiny worms, but are very
difficult to see. Gill Flukes are contagious and should be treated
immediately. Gill Fluke eggs are resistant to medications, but the larvae
and adults are susceptible. This disease is most common in younger fish and
fry, who are more susceptible to the parasite.
Velvet Disease has a lifecycle like that of Ich. Velvet also uses light as
an alternate energy source, shading your tank may also help speed
Trichodina is a ciliated protozoan parasite that infests most freshwater
tropical fish, goldfish, koi, and saltwater fish. Trichodina is too small to be
seen without a microscope, up to 100 microns in diameter. Trichodina
infestations are "slow-moving," gradually affecting fish if untreated.
The parasite initially attacks injured fish but in crowded aquariums will host
on healthy fish slowly debilitating its host. Dead fish must be removed
quickly as the cell leaves the body within two hours.
Popeye or Corneybacteriosis will cause swelling in the head of the fish
causing the eyes to protrude outwards. Popeye is a condition and not an actual
disease. It can affect one eye or both. Possible causes are poor water quality,
trauma, internal bacterial infection and also Gas Bubble Disease.
Gas Bubble Disease:
The condition is brought on by oversaturation of oxygen in the fish tank.
Specifically the balance of dissolved gases being upset by the over production
Hypoxia: (Oxygen Starvation)
Many of these signs are the same as for a gill problem so a test for Dissolved
Oxygen has to be made to be conclusive. Running a test for dissolved oxygen
content should be conducted in early morning hours since that is the time of
day when levels are usually lowest and they are normally highest in late
Finrot can occur as a result of an injury, as a secondary infection once
the fish has been weakened by another disease, or in some cases, as a
primary infection (bacterial). As a bacterial infection or as a fungal
infection, the fins or the tail will rot more evenly and is more likely
to produce a white 'edge'. Sometimes, both types of infection are seen
together. Infection is commonly brought on by bad water conditions,
injury, poor diet. Finrot starts at the edge of the fins, and destroys
more and more tissue until it reaches the fin base. If it does reach the
fin base, the fish will never be able to regenerate the lost
tissue. At this point, the disease may attack the fish's body directly.
Aeromonas bacterium, which infects a fish via skin parasites or when it
ingests feces from infected fishes or feeds on the remains of dead fish.
Bacterial infection often brought on by poor water quality or as a result of
the fish being weakened due to parasitic infestations.
Dropsy is not, in itself, a specific disease, but rather refers to a condition. A sudden swelling of the abdomen (scales may stick out) is known as acute dropsy while a slow swelling of the abdomen is known as chronic dropsy. The actual cause of this swelling could be indicitive of any one of several conditions:
Neon Tetra Disease:
Neon Tetra disease is more common than many
aquarium enthusiasts realize, and affects species
beyond Neon Tetras. Named after the fish that it
was first identified in, the disease strikes members
of the tetra family most often. However, other
popular families of aquarium fish are not immune.
The disease cycle begins when parasitic spores enter the fish after it consumes infected material, such as the bodies of dead fish, or live food such as tubifex, which may serve as intermediate hosts. Once in the intestinal tract, the newly hatched embryos burrow through the intestinal wall and produce cysts within the muscle tissue. Muscles bearing the cysts begin to die, and the necrotic tissue becomes pale, eventually turning white in color generally starting within the color band and areas along the spine. It is not unusual for the body of the fish to have a lumpy appearance as the cysts deform the muscles.
Swim Bladder Disease:
Buoyancy problems are caused by a wide variety of disorders. Deformed bladder,
parasite infestation, bacterial infections and tuberculosis. Two of the more
common reasons are either constipation or dry food is eaten quickly and swells
up in the fish's intestine and keeps the fish from controlling its swim
bladder properly. Isolating the fish to a hospital tank in which the
water is shallow is a wise thing to do until the cause can be
determined. The shallow water also provides relief for the fish.
Cloudy eyes, Bloody patches and sluggishness, are indications that metallic
poisoning may have occured. Also, using aerosol sprays directly around your
tanks can have an adverse affect. The same with having soap residue and perfume
on your skin that you expose to the tank water. If in doubt, as to what is
wrong always suspect poisonious toxins.
Fish actively maintain a natural balance of electrolytes in
their body fluids. Electrolytes such as potassium, sodium, chloride, calcium,
and magnesium are removed from the water by chloride cells located in the
gills. These electrolytes are essential for the uptake of oxygen and release
of carbon dioxide and ammonium across gill membranes. The lack of electrolytes
can cause serious health problems to the fish. Osmotic shock interrupts healthy
gill function by reducing the intake of oxygen and the release of carbon
dioxide and ammonium from the fish. This can lead to the loss of electrolytes
through the gills. Also, a fish who has had their slime coat disturbed can
lose electrolytes through their skin increasing the possibility of a fish
contracting Osmotic Shock.
A fish may exhibit wasting or other loss of weight for no apparent reason. A
tubercular fish has a normal appetite, but as internal organs become damaged
by the disease, the fish slowly loses weight to the point where the fish's
head will appear too big for her body. If a nodule forms under the fish's eye,
it may protrude, causing pop-eye. These nodules on other parts of the body
develop into ulcers. Unfortunately, by the time the symptoms become noticeable,
the fish has been infected internally for quite some time.
**Tuberculosis is becoming a more common occurrence in recent years, and
is an especially serious disease. It is very contageous, and in some
cases, it is also transmittable and dangerous to humans.
The utmost care must be given to prevent the spread of this disease to
humans or other fish. If you suspect your fish may be afflicted with this
disease, remove them immediately from the tank. Anytime you have any open sores
or cuts on your hands, wear plastic gloves regardless if you suspect
Tuberculosis might be present or not. Unfortunately, Tuberculosis is very
difficult to treat in fish, and is most often fatal.
Columnaris: (Mouth Fungus)
Columnaris is often confused with a true fungus infection. Columnaris disease
is caused by a bacteria Flexibacter columnaris and not by fungus.
Columnaris can be highly contagious so any suspected fish should be isolated
as soon as possible to begin treatment.
True Fungus Infection:
Fungal infections usually occur as a secondary infection, invading tissue already damaged by bacterial and parasitic diseases. Fungus also attacks fish that have been weakened by rough handling, shipping, exposure to ammonia and nitrite, improper netting, and malnutrition. Fungal pathogens use digestive enzymes to feed on the fish tissue. The enzymes damage nearby healthy tissue, allowing the disease to spread.
Common name: Cottonmouth disease, Cotton-wool disease