| This
is a brief guide to common Koi Health issues and common
Koi diseases. It is intended as general information
and should not take the place of a good book on the subject
or professional help. For a more detailed guide,
visit
Koi
Vet.
Or place a post in our
Unless otherwise stated, most of these Koi Health problems
can be treated using commercial remedies, ask a dealer
for advice if you don't know which one to buy.
Sliminess of the skin.
A grayish white film of excess mucus on the body. This
is a reaction to protozoan parasites, notably Ichthyobodo,
Trichodina and Chilodonella. Other symptoms of infection
by these parasites are scratching and leaping followed
by lethargy and failure to eat. Further risks are secondary
bacterial and fungal infections of wounds caused by scratching.
The parasites are particularly active in spring when Koi
are still recovering from winter.
White spot (Ich).
Caused by Ichthyopthirius multifiliis. The white spots
on the skin, gills and fins are individual protozoan cells
that are under the skin and feed on the body fluids and
cells. They then punch out of the skin and fall to the
bottom of the pond, collect together and begin breeding,
the offspring then re-invest the fish. As well as white
spots symptoms are scratching and swimming into the water
inlet, failure to feed and lethargy. It is fatal if untreated.
Fortunately commercial white spot remedies are widely
available.
Anchor worm.
Crustacean parasite, Lernaea . The juvenile stages settle
in the gills of Koi, when they mature they mate and the
male leaves the Koi, the fertilized female settles on
the body of the Koi and continues to grow, becoming the
familiar worm shape. The female buries into the skin and
underlying tissue to hold on. The damage caused can become
a target for bacterial or fungal infection which can spread.
Cotton wool disease.
Another bacterial infection. The common name comes from
the white tufts that develop around the mouth and spread
to the body and fins, often leading to ulcers and a thin
appearance. Flexibacter is the bacterium which causes
this disease. Treatment with anti bacterial medicine is
usually effective.
Skin and gill flukes.
These are the fish equivalent of fleas. They are two different
types of flukes, but despite of their names both can be
found on the body and the gills, feeding on mucus. They
use hooks to hold onto the Koi, this causes irritation
and in a weak, sick or stressed Koi can become a problem. |
Fish lice.
Argulus another crustacean parasite, round and up to 1cm
wide. They have a sucker to hold on to the Koi with needle-like
mouth parts which they stick into the Koi and inject a toxin.
This causes intense irritation to the Koi and they scratch
and jump and can cause bacterial infection. If they infect
the gills they cause severe damage and often death. Most
antiparasite remedies will not kill fish lice, a strong
chemical is needed which is not freely on sale. Ask a professional
dealer or vet.
Gill maggots.
Are the mature females of the parasitic crustacean Ergasilus.
Heavy infestations can cause severe damage, eroding the
gill filaments and allowing secondary infections to develop.
Saprolegnia fungus.
One of the most common fungal infections of Koi. The fungal
spores will grow anywhere on the Koi, including the gills,
initially germinating on dead tissue. Their threadlike
hyphae release digestive juices which break down the tissue
so the fungus can absorb it, as the fungus grows these
juices start breaking down living tissue. Fungus on the
body appears as cotton wool like growths, it is hard to
tell if a Koi has it in the gills, but if it hangs at
the surface gulping for air it is likely.
Carp pox. A virus that produces solid waxy lumps on Koi.
It will not kill Koi and is generally harmless, but can
look unsightly. It is most often present in small Koi
and in cold weather, clearing up disappearing when Koi
grow and in the spring when water temperatures rise.
Finrot and ulcers.
A number of bacteria are associated with finrot, lesions
and internal hemorrhaging, notably Aeromonas and Pseudomonas.
Ulcers usually start at the site of an injury, the bacteria
then infect it causing further damage, and fungal infection
can also occur. Such holes result in osmoregulatory problems,
leading to damaged kidneys and death if not treated. It
is worth adding a weak salt solution to the pond as well
as anti bacterial remedy (MelaFix®),
a concentration of 3gm per litter will help to restore
the osmotic balance and reduce strain on the kidneys (make
sure that the salt is fully dissolved before you add it
to the pond). Finrot is easily noticeable, the fins and/or
tail look chewed and are red at the edges. Secondary bacterial
and fungal infections can develop.
Dropsy.
Raised scales (rather like a pine cone) and eyes standing
out from the head. A sign of a number of conditions, may
be congenital heart or kidney failure or an internal bacterial
infection. Bacterial dropsy is infectious so treat with
an anti bacterial remedy and if possible isolate affected
Koi. |
