Diseases
Hole in the Head Disease--
Septicemia--
Ich--
Velvet
Disease--
Gill Flukes--
Skin
Flukes--
Slime Diseases--
Anchor
Worm--
Fish Louse--
Finrot--
Introduction
It is often said, but not said enough, that the best cure for any
disease is it's prevention. In the case of Oscars (and any aquarium
fish, for that matter) it is doubly true. Our tropical fish live in a completely
closed system that is totally dependent on us. There is nothing
that enters or leaves the aquarium without our intention, help or inattention.
If we have a "healthy" aquarium and suddenly a disease appears, it is always
our fault. With careful aquarium maintenance there is no reason for disease
to appear, except in the rarest of cases. I quote Dick Mills in his book
You
and Your Aquarium:
As diseases aren't always easy to cure, prevention is the key factor
in fish health care. The good health of your fishes is very dependent on
their environment -- poor water conditions, stress or incorrect feeding
can lead to illness. The fishes have no control over their conditions,
and it is therefore up to you to manage the aquarium correctly. This involves
various important procedures to prevent the introduction of disease: quarantining
new specimens, handling and feeding the fishes correctly, preventing the
introduction of poisons or predators, keeping the heating, lighting, air
supply and filtration systems functioning properly, and last, but not least,
ensuring that the water is clean, fresh and correctly balanced for the
fishes in it. And since plants are a vital part of a freshwater aquarium's
"eco-system", caring for them is important, too.
I cannot overemphasize the importance of a quarantine tank. Before
putting anything new in our Oscar tank, with the exception of prepared
foods, it must be placed in another tank and watched for a couple
of weeks. Live food, new fishes, any decorations, plants, gravel, anything.
I suggest even looking at the quarantine tank before you look at your Oscar
tank! :-) Then if a new fish develops a disease, you've caught it before
you've infected your Oscar.
Keeping a quarantine tank cycled, when it is being used for your Oscar
aquarium, is a simple matter of using it to keep your feeder goldfish.
Clean Hands
Clean hands, happy Oscars. But avoid washing your hands in heavily
perfumed bath or deodorant soaps, or anti-bacterial soaps. A good soap
would be dish detergent, because it is designed to rinse completely off.
No Smoking
No smoking, staining furniture, painting etc. close to your aquarium!
That air pump will suck up those fumes and bubble them right through your
Oscar's water. Additionally, avoid using household cleaners to clean the
aquarium's glass. The Oscar doesn't need a megadose of ammonia!
No Loud Noises
Try to position your aquarium away from slamming doors, loud stereos,
etc. Noise can increase your fish's stress level and make it more prone
to disease.
Subtle Lighting Changes
Tropical fish can be frightened by the sudden lighting or darkening
of the tank, increasing it's stress level. In the morning, allow the room
to lighten up a bit before you turn on the aquarium lights; and at night,
leave the room light on for a few minutes after you shut down the tank
lights.
Water Changes
Although I've said before that I sometimes wait 60 days to do partial
water changes, I can't say that I recommend it. I depend on the outcome
of my ammonia and nitrite tests to determine when a water change should
be done, but it's probably a better idea to do them weekly or bi-weekly
as a habit. One advantage of doing it weekly is that your Oscar gets used
to it and it becomes less stressful. Another is it gives you the opportunity
to vacuum the gravel more often. Whatever type of schedule you use, it
is very important to stay faithful to your water changes.
Remember to unplug your aquarium heater before you change the water!
Don't Overfeed
One of the most common mistakes even experienced aquarists make
is to overfeed the tank. Uneaten food decomposes and fouls the water in
your aquarium very quickly. Feed as often as you wish, but feed only what
your fish will consume in a few minutes. This is especially critical in
an Oscar tank, because Oscars are very messy eaters anyway.
Top
Septicemia
Septicemia is a little discussed but very common
internal ailment. In very dirty water, it can occur on it's own; however,
it is normally the result of another disease. Bacteria from the primary
disease enters the bloodstream of the fish causing inflammation and damage
of internal organs. Blood vessel and heart tissue damage causes the leaking
of fluids into the abdomen, producing "dropsy".
Affected fish will have reddening at the base of the fins and around
the eyes, be very listless and disoriented, and will not eat.
Remedy
Frankly, the best option here is to euthanize the fish. In this state,
disease has advanced too far to be treatable, and the other fish in the
aquarium need to be protected.
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Finrot
Finrot is a disease that very rarely attacks Oscars,
but is more common in heavily colored fishes like Mollies, and fish with
a well defined display attribute in the fins, like Millions Fish or male
Betta Splendens. The cause of Finrot is usually a very dirty aquarium and/or
a very poor diet. In an Oscar aquarium, an additional cause can be fin-nipping
from another aggressive species in an ill-planned setup.
Remedy
Most importantly, correct the cause of the disease. Treat the affected
fish with a proprietary remedy. In severe cases, it may be necessary to
take the fish to a vet, who will trim the diseased part under anaesthetic
and treat with an antibacterial medication. Finrot is a good example
of a disease where the best remedy is it's prevention!
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Fish Louse
Argulus is a crustacean that swims from host to host.
It anchors to the fish with strong suckers and penetrates the skin with
a poison spine. These parasites are visible to the naked eye and are approximately
a quarter inch in diameter.
Remedy
Your Oscar will need to be removed from the tank and placed on a wet
cloth. He will survive for one or two minutes. Remove the parasite with
tweezers. Place the fish in your quarantine tank or other suitable hospital
aquarium, so that you can treat the original aquarium with a proprietary
remedy for fish lice that will kill any remaining larvae.
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Skin Flukes
Skin Flukes, Gyrodactylus, are related to Gill Flukes
but have a different life cycle, and do not have the same resistance to
treatment. Colors will fade and the skin will redden, and the fish will
scrape against objects in the aquarium. Treat the aquarium with a proprietary
remedy. A hospital tank is not necessary.
Top
Hole in the Head Disease (HITH)
9-27-98
UPDATE
HITH attacked one of my Oscars recently. Up to this date, I
had never actually treated a case of HITH. Fortunately, what I'd learned
through study and word of mouth about the disease must be accurate, because
I discovered that the outbreak was very treatable and the lesions, although
aggressive, healed over very quickly. From the onset of the disease to
the healing of the lesions took only about 2 weeks. Here's what happened:
One of my 50 gallon aquariums has two grown Oscars (Felixia and Napoleon)
and a 5 inch Dempsey, in addition to a 12 inch Pleco and a little 3 Spot
Gourami that the Cichlids ignore for some reason. At about the beginning
of August, two holes began to appear just to the front and a little to
the sides of Felixia's dorsal fin. At first I dismissed them as injuries;
sometimes Cichlid tanks do get a bit aggressive. There was tufts of mold
over both lesions at this time. Usually, injuries like this heal up in
a week or so; however, these holes continued to grow. A week after the
disease first appeared, there were several additional lesions beginning
to grow on her, particularly by the gill covers and along the top lateral
line. (Cichlids, you may recall, have two lateral lines instead of the
usual single line.) The mold disappeared from the original holes, which
continued to grow rapidly. It was at that time that I realized I had a
case of HITH.
Felixia appeared to be feeling no discomfort during the onset. She ate
normally and exhibited none of her usual signs of stress (rapid breathing,
lying on the bottom of the aquarium, aggressiveness, etc.). I tested the
water for nitrites and ammonia. After I was certain that aquarium conditions
were ideal, I headed off to the local LFS, where I got a couple packages
of Clout, a general aquaria medicine that treats protozoan and viral
diseases. I removed the activated carbon from the filter, ceased feeding,
and treated the aquarium with Clout for 4 days. After the first day the
holes ceased growing, and during the rest of the treatment they appeared
to "dry up", so to speak. After the treatment, I did a 50% water change
and resumed normal feeding. Over the next 3 or 4 days, the lesions healed
completely and are covered with a new layer of scales. It's evident where
the larger holes were, because there are slight indents in those areas,
but they are completely healed.
So, how did Felixia get HITH? I'm not certain. The only recommendation
I did not follow from the discussion on HITH that follows is feeding a
diverse, interesting diet. Felixia was eating only a couple of varieties
of processed foods in addition to the occasional feeder goldfish.
3-3-98
In the past couple of months, the following section on Hole in the
Head Disease has generated more response than any other portion of the
OSCAR Study page. Unlike diseases such as Ich, it is difficult to find
authoritative sources that agree on HITH's cause and cure. Most of the
Emails I've received lately, and much of the discussion in the Usenet newsgroups
I participate in, however, are leaning heavily toward diet being
the primary cause. However, the majority of experts (books, etc.)
believe the cause is the Hexamita protozoan that is found in the lesions.
As a matter of fact, many experts call HITH "Hexamitiasis". One can assume
that poor diet is a stress-causing factor that allows Hexamita to invade.
But are the lesions themselves invaded by Hexamita, or caused by
Hexamita? This is the point where in studies we see the most confusion.
Nevertheless, it is commonly accepted that attending to regular maintenance
to keep water quality/temperature correct, and feeding a diverse, interesting
diet, almost always heads off this disease.
Head and Lateral Line Erosion, known as Hole in the Head disease,
is a fairly common threat to Oscars. It also effects Discus and other Cichlids,
and, reportedly, many saltwater fish. There has never been a definitive
answer to it's causes (see note above), although there is a lot of agreement
as to certain conditions that almost always exist with the infection. Those
are:
--The absence of a varied diet. It has been said that the absence
of Vitamin C in the diet can be a contributing factor. Feeding from a variety
of sources, including plant, will help.
--The presence of activated carbon in the filter. It's unclear
to me whether the carbon would be a cause of the disease, or whether it
removes a substance that may prevent it; but word is that aquarists that
avoid activated carbon have had little or no problems with HITH. (Your
Mileage May Vary: I have never seen this demonstrated, but it's a popular
claim among some aquarists.)
--Elevated Nitrate levels. This is unproved, but many people
contend that elevated levels of Nitrate can cause HITH. Nitrate can be
lowered by regular and frequent water changes, and live plants.
--Stress and poor water quality.
HITH, untreated, can lead to certain disfigurement and sometimes death.
The fish does not seem to be in any pain, because there is no scraping
or change in mood associated (that I have observed, but I am open to correction).
It is characterized by an approximately 1/8 inch deep crater that grows
in the forehead and along the lateral line. Hexamita is always found in
the hole.
Remedy:
The cure for HITH may be as unclear as the cause, but eliminating possible
causes certainly is the first step: Begin feeding a more varied diet, concentrating
on Vitamin C. Do regular frequent water changes and pay special attention
to the aquarium's water conditions. Remove any sources of stress; loud
noises, aggressive tankmates, etc. Finally, to deal with the infection
of Hexamita, find a commercial medication containing metronidazole.
During treatment with this medication, avoid the use of activated carbon
in the filter.
Top
Velvet Disease
Oodinium limneticum, known as Velvet Disease, is
a tiny parasite seen as a gold "dusting" on the fish's skin. It roots to
the fish, drawing nourishment. Additionally, like plants, it contains a
pigment that uses light as an energy source. Velvet very rarely attacks
an Oscar tank because it needs rancid water conditions to thrive; it is
more common in smaller, closed environments like Bettas and certain Annual
Fishes (Killies) are forced to endure.
Remedy:
Remove activated carbon from the filter, and treat the entire aquarium
with a proprietary medication. You may also want to shade the aquarium
during treatment.
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Gill Flukes
Gill Flukes, Dactylogyrus, are tiny, worm-like flukes
that attach themselves to the fish's gill membranes. Your fish will scrape
against aquarium decorations, breathe rapidly at the surface of the water,
and a mucus will form over the gills. In an advanced state, the gills will
be eaten away.
Remedy:
To treat Gill Flukes, your fish will need to be removed from the aquarium
into a hospital tank. Completely break down, clean and disinfect the main
aquarium. The reason for this is that the flukes lay eggs that fall into
the gravel, and these eggs are very resistant to treatment. Give affected
fish a short-term formalin bath, then treat the hospital tank weekly until
all the larvae are killed. Note: Add the proprietary remedy to the hospital
tank before adding the affected fishes.
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Freshwater White Spot Disease
Otherwise known as Ich, Ichthyophthirius
is one of the most common diseases in a freshwater tropical aquarium. It
is a parasite that is visible to the naked eye. It lives a cyclical lifestyle,
which makes it a fairly easy disease to treat when done correctly. It appears
as white spots, up to 1 mm in size, on the fish's skin. When it is on the
skin, it cannot be treated; but this parasite must leave the host and sink
to the floor of the aquarium to reproduce. While on the floor, it secretes
a jelly-like covering around itself and divides into many young. When this
covering bursts, the new parasites seek a new host.
Remedy:
Remove activated carbon from the filter, and treat the aquarium with
a proprietary medication. The infection cannot be treated while the parasite
is on the host or while it is in the jelly-like covering. Therefore, since
Ich's cycle takes approximately 5 days to complete, the medication needs
to be administered over a period of ten days to be certain to kill all
of the parasites.
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Slime Diseases
Slime diseases are caused seperately or in concert by three protozoan
parasites: Chilodonella, Costia (Ichtybodo), and Cyclochaeta
(Trichodina). Initially, your Oscar will dull in color because of the
overproduction of mucus; followed by the fraying of the fins, weakness
and disorientation, gill damage and death. Caught early (before it spreads
to the gills), it can be treated with a proprietary remedy. This adds a
lot of importance to your ability to keep a careful eye on your fish!
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Anchor Worm
This crustacean, Lernaea, has an anchor-shaped head which
it buries in the fish's tissues. It is large enough to be clearly visible
on the fish, and when it falls off it may leave an infected sore. Your
Oscar will scrape against objects in the aquarium, and there will appear
whitish-green threads that will hang out of his skin.
Remedy: The fish needs to be removed from the tank, and then
the Anchor Worm removed with tweezers. An Oscar will not be injured if
kept out of the water for two minutes or less. Place him in very clean
water, treated with a proprietary remedy that will protect him against
a fungus attack.
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