koi diseases
Koi Diseases How to diagnose and treat common koi fish diseases
Koi fish are very hardy, robust fish and don’t often once become sick once they have settled into the koi pond.
koi disease occurs in ponds as fish fall prey to parasitic, bacterial or fungal attacks.
The causes of koi fish diseases varied and can range from a sudden drop in water temperature, predator attacks and spawning to name a few.
No matter what the cause of the koi diseases, one thing remains constant – the sooner you recognize and begin to treat the problem …the more likely you will be successful treating the koi diseases.
Regular pond maintenance and water-quality checks help keep diseases away from fish, but illnesses still occur, even in the best-kept ponds.
The first sign of a problem may be a fish floating at the surface, by which time it is probably too late for effective treatment.
For this reason, it is vital to set up a routine for examining fish; feeding time provides an ideal opportunity to check their appearance and behavior.
So how do you know if you have a sick koi fish? Sometimes the signs that a fish is sick are very subtle, such as one fish segregating itself away from other fish, or not eating very much.
As time passes and the koi disease gets worse, the symptoms become more obvious and may spread to other fish.
Environmental problems
The health of pond fish influenced by environmental conditions.
During spells of hot weather, for example, evaporation can lower water levels, which has the effect of concentrating dissolved nitrogenous waste.
Atthe same time, elevated temperatures drive oxygen out of the water; the combination of nitrate and oxygen stress can be fatal, especially for larger fish.
Many of these problems can avoided by topping off water levels during the summer, and incorporating a pump and filter; these improve water quality, break down waste, and increase oxygen content by creating water movement.
Overstocking a pond, especially if it is not well established, places great stress on its occupants, and fish may succumb to usually benign bacteria that are present in the water.
Overfeeding is another common environmental problem, especially in temperate areas in the spring and fall; uneaten food decomposes in the water, encouraging populations of pathogens.
It turns out that Koi is quite hardy for ornamental fish. But, on several occasions when there is irregularity in water quality, things may become quite rough for them.
Among the most major disease for Koi is Ich parasite or white spot disease.
This disease will make the fish look like they have been sprinkled with white salt all over their body.
This parasite will attach to the skin, and eat them alive for several weeks before they detach themselves and move to other host.
There are several disease affecting them as other fish, but there is one virus, which affected Koi and common carp but not other species.
That viral disease called Koi herpesvirus (KHV) or cyprinid herpesvirus 3. Most of the fish infected with this virus will die but some may survive.
Those who survive will be the carrier and may send the viral infection to other non-infected fish.
In this case, most of the breeders that have Koi diagnosed with KHV in their farm will need to take harsh action to cut all the population to avoid the spreading.
fish diseases pictures
Gill rot fish diseases pictures
This disease occurs the most of all the koi diseases.
Irrespective of conditions of breeding or sizes of koi, it occurs.
It often does at high temperature above 20 degrees centigrade, but sometimes below the temperature, too
The disease advances . before the diseased koi fish loses its weight, it dies, that is before the fish shows any symptom, it dies.
In such a case if you open the gill, you will find red gill filaments turn grey or muddy, or some of them broken.
The germ is columnaris. Its treatment is oral administration of sulfa drugs or antibiotic substances or a medicated bath of furan drugs.
Aquatic terramycin is very useful
fish diseases pictures Anchor worm disease
Red swellings appear under the scales.
When the tip of a swelling pulled, a worm with an anchor-shaped top comes out.
The worms stick to fins, mouths and the hypoderm.
Sometimes fifty or sixty worms live on a fish and weaken it to death.
Dipterex is efficacious to exterminate them.
fish diseases pictures raised scales
Liquid stays under the scales and puses them up. The scales bristle up. liquid stays also in the abdomen and the body swells. The diseased koi fish looks like a pine cone.
First a part of the body affected, but gradualy the disease spreads all over the body. Eyes of the diseased koi fish protrude.
It breathes hard, swimming around in crazy manner.
After a day or two the fish dies, overtunring on its back.
The Doitsu happens to affected by the disease, but it recovers
Its causes supposed to be some bacteria, interruption in blood circulation caused by a disease blood vessel or internal orga, some medicines and excessive eating of live foods.
It occurs often in the spring when oxidized pupae given to koi.
When the water temperature is high, it breaks out. Any fish, either fry or adult, affected in dirty water.
Sulfa drugs, anitbiotics and furan drugs are efficacious. It is also helpful to break blisters and apply monafracin with Dipterex to the part.
It is important to find the disease in its early stage, otherwise, it will be difficult to cure it.
White spot disease 
Bladder disease 
A koi with this disease struggles to go up to the surface, sinks down to the bottom or turns itself upside down.
It loses the sense of equilibrium and cannot swim in a normal position.
The causes are that swelled intestines press the air bladder because of indigestion, that indigestion makes the body weak as the temperature falls and that fatty degeneration of an air bladder.
It is difficult to cure it.
Tumor of reproductive organs 
Huge koi are apt to be affected by the disease. The diseased koi has a large tumor in its abdomen which gradually gets larger and affects the skin Finally the tumor breaks and the fish dies.
Especially the tumor in the first half of the body seems to be malignant. It is a malignant tumor of the genital gland.
Particles like cancer virus are found in it. The tumor should be found and removed in its early stage.
Examination of the texture is necessary as soon as it is found.
Spinal paralysis 
Agricultural chemicals such as Dipterex, over-feeding or electric shocks from the submersible pump motor or lighting cause koi spinal paralysis.
They become crooked. It is difficult to cure it, but sometimes it heals naturally. Keeping the diseased fish in a large pond is an effective treatment.
Gas bubble disease 
It occurs when the water temperature is high in the summer. Fry often suffer from it in green water.
Gas bubbles appear on the head or the fins and sometimes eyes protrude, supersaturation of oxygen in water causes the disease.
It can be prevented by adding water to the pond or making a shade over it.
When aeration or heating is working in a tank, they must be well-controlled not to cause the disease.
Dystrophy of the back 
The back of a diseased koi caves in along the dorsal fin. The line of the backbone shows itself clearly.
Its mortality rate is not high. Koi affected by the disease are weak against oxygen shortage or wintering.
They are apt to get scraped or molded. The cause is said to be degenerate fat of pupae.
A report tells the disease resembles men’s sugar diabetes pathologically. Vitamin E drugs are used for its treatment but it is very difficult to cure it.
Health concerns
Regular pond maintenance and water-quality checks help keep diseases away from fish, but illnesses still occur, even in the best-kept ponds.
The first sign of a problem may be a fish floating at the surface, by which
time it is probably too late for effective treatment.
For this reason, it is vital to set up a routine for examining fish; feeding time provides an ideal opportunity to check their appearance and behavior.
Environmental problems
The health of pond fish is hugely influenced by environmental conditions. During spells of hot weather, for example, evaporation can significantly lower water levels, which has the effect of concentrating dissolved nitrogenous waste.
At the same time, elevated temperatures drive oxygen out of the water; the combination of nitrate and oxygen stress can be fatal, especially for larger fish.
Many of these problems can be avoided simply by topping off water levels regularly during the summer, and incorporating a pump and filter; these improve water quality, break down waste, and increase oxygen content
by creating water movement.
Overstocking a pond, especially if it is not well established, places great stress on its occupants, and fish may succumb to usually benign bacteria that are present naturally in the water.
Overfeeding is another common environmental problem, especially in temperate areas in the spring and fall; uneaten food decomposes in the water, encouraging populations of pathogens.
Dealing with disease
Disease-causing bacteria, fungi, and parasites may be introduced into the pond whenever it is stocked with fish or plants.
Undesirable organisms can also be brought in on the bodies of animals, especially wading birds, that move from pond to pond.
These can multiply and cause serious harm
before their presence is detected, and eliminating them can be very difficult. A table of the most common conditions seen in pond fish, as well as treatment strategies, follows
If your fish are affected, you are most likely to first notice changes in their behavior and feeding patterns; a sick fish may, for example, distance itself from others, or take refuge behind a plant.
If disease is suspected, affected fish should immediately be removed from the pond and kept in isolation, preferably in a large aquarium (see above). Here you can inspect the body close-up and check for symptoms of disease or parasite
infestation.
Fish lice will be visible in this environment, and you should also be able to detect gill flukes much earlier than would be possible in a pond.
Treatments can be carried out in the tank itself, or in smaller baths, and the fish’s progress can be readily monitored before reintroduction to the pond.
If a fish is affected with a disease or parasite, check other fish to determine whether there is a general problem in the pond or the disease is an isolated instance.
Look out, too, for secondary infections. Sometimes the entire pond needs
treatment with commercial chemicals, but often it is sufficient to treat individual fish.
Check all water-quality parameters before reintroducing the fish; minimizing environmental stress will help prevent recurrence of the condition.
Certain diseases, such as the rapidly spreading koi herpesvirus (KHV), are untreatable, emphasizing the importance of isolating new fish before introducing them to a pond and seeking professional advice if many fish become ill.