This is one of the
problems of having a heated system. I fully understand that Koi are not cold
water fish but are more temperate and do benefit from a cool
The objective of most Koi keepers having purchased a
beautiful specimen, the quest is to help the Koi to grow to its full potential
by providing it with a high protein diet and an expansive pond. The pond may
even benefit from an additional source of heating to provide the Koi with
healthy growing conditions.
If all goes to plan, the Koi will increase
in length and volume at similar rates and grow into fish displaying
However, Koi will occasionally adopt an
abnormal growth pattern, where its volume continues to increase without the
associated increase in length.
This fat fish has an ovarian tumour. It is easily
distinguished from a pregnant female as the swelling is mainly near the rear
end and usually on one flank more than the other.
unsightly, such Koi will often swim with apparent discomfort, wriggling with
difficulty and adopting a strange pose in the water. These symptoms are quite
common, especially in older fish.
A fish suffering from a tumour is not
likely to become as obviously bloated as a dropsied Koi, and it is only likely
to affect a localised area of the fish. A tumour is likely to manifest itself
as a lump, and the swelling may appear to one side if the Koi is viewed
directly from above. As with dropsy, there is little remedial action that can
be-carried out. Only the ovarian tumours have a tendency to swell the belly of
which is in anaesthetic, has very visible swelling, wich became visible over
six weeks. This is due to a tumour of the gonads, and you can see more on the
Mature female Koi will
naturally fill-out from spring through to summer when, if stimuli for spawning
occur, they will spawn naturally in the pond.
It is quite common for
older female Koi to reach July or August without spawning. Koi will respond to
number of environmental stimuli, like sudden changes in temperature and water
quality, or suitable mature males. If climate changes are not common during the
summer, or the Koi are in heated ponds, then Koi will not be given the means
through which to spawn - heated systems have their drawbacks.
Fatty degeneration of the internal organs
grow Koi as quickly as possible, you may have fed them excessive quantities of
energy-rich food, which will result in fat being deposited around the gut and
internal organs. If this is the cause of the bloating then the majority of Koi
in a pond are likely to exhibit obese symptoms.
The remedy is to put
your Koi on a diet. Change their food to a low-energy autumn/winter variety.
The belly of a Koi may bulge due to a build up of tissue fluid around
the abdomen area. This can be caused by an internal bacterial infection or the
malfunctioning of the kidneys. Behaving like a fluid-filled balloon, the volume
and pressure within the Koi can cause blood capillaries to become visible in
the skin and the eyes to protrude. This condition can easily be mis-diagnosed
as Koi being spawn-bound, but if scales protrude from the sleek lines of the
Koi's body then this is a positive identification of a Koi suffering from
dropsy. This illness is often terminal and can pose risks for other Koi in the
same pond. Therefore, the affected fish should be isolated and monitored. If
the affected Kois health deteriorates further it should be put to sleep
with an overdose of anaesthetic.
Also many fat obese KOI die of
arteriosclerosis which is thickening and hardening of the arterial walls,
resulting in impaired blood circulation which leads to death.
This fish has an ovarian tumour or
fatty degeneration of internal organs. A post-mortem is needed to confirm
which. Both are untreatable at this advanced stage.Prolapsed bowel.
This has many causes,
most are unknown at this point in time, but one is over feeding with live food
and two is feeding maggots.
Thanks go to Ben Helm's
web site 'The Water Gardener's Bible' :