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Koi health

Koi are susceptible to various diseases that may crop up from time to time. Very few Veterinarians specialise in koi health and one cannot just put a koi on a lead and take it to the Vet. If you are lucky enough to find one, only symptomatic treatment can be effected. Koi health experts are also not readily available and it is therefore essential that the koi hobbyist should be able to spot a problem in the pond early and know the basic treatment for the more common diseases. It is also necessary to understand the root causes and have the knowledge to rectify that underlying problem. The articles on this we-site are specifically aimed on equipping the koi keeper to diagnose and rectify these problems. One of the underlying causes of koi disease is water quality and stress. To address this, papers relating to pond dynamics, filtration and the nitrogen cycle authored by Chris Neaves, are also included under Chris on Koi ,else where on this web-site.

General Appearance
When the koi keeper observes the collection, certain tell-tale signs may be exhibited by the koi. It was therefore deemed necessary to include some here to alert the owner that something is wrong.

Bottom swimming
Fish that stays near the bottom, particularly if it stays away from the rest of the collection is either suffering from swim bladder disease, are infected with parasites or a bacterial disease

Bloated appearance
This does not refer to the normal female distended with eggs. Abnormal bloated appearance, especially if accompanied by protruding scales, is normally indicative of Dropsy. Dropsy can be caused by an infection, inflammation, kidney failure or rupture of the ovaries.

Changes in body shape and weight loss
Chances in body shape where a bulge is noticeable on one side of the abdomen may indicate a tumour. Major surgery will be required and the success rate is very low. Weight loss to the extent that a fish may look emaciated may be due to bacterial infection, parasites or the dreaded Mycobacterium that is potentially contagious to humans. Smaller waxy and wart-like lumps may be caused by a viral infection.

Changes in eyes such as sunken eyes, protruding eyes and cloudiness
Cloudiness can be an indication of a damaged/ injured eye or an infection by the parasite, Ligula. Protruding eye can be a symptom of damaged gills, liver and kidney. Pop-eye can also be an initial stage of Dropsy

Clamped fins
Clamped fins signal an illness, stress, incompatibility, or parasite problem. A fish swimming with fins close to the body should be selected for a parasite check.

Colour changes
Colour changes which are genetically controlled are normal. Colour can also change through the effects of diet, hormonal factors, environmental factors and overall health. Reddening of the skin is indicative of a parasite or bacterial infection.

Damage to the skin and body
Damage to the skin, fins, eyes, mouth and gill covers, as well as missing scales can be due to various factors such as parasites, bacterial infections, injury or predators.

Fin erosion
Fin erosion can be caused by parasites, bacteria as well as harsh chemical treatments. Chemical burns are normally seen as white edges to the frayed fins while infections will cause red edges to the fins.

Kinked/crooked back
Kinked/crooked back are associated with a lightning strike, electrical shock, and vitamin deficiency and sometimes overdosing with organophosphates. Rough handling of very young fry, frequently result in crooked back as the fish develops.

Loss of appetite
This may occur in cold weather but it may also be an indication of a bacterial infection, parasites, unacceptable water quality and stress

Rapid/slow movement of the gills
Rapid respirations can be a sign of low oxygen in the water, toxins in the water, and parasites on the gills or bacterial gill infection. Slow respiration can de seen when a fish is anesthetized or dying.

Fish may spontaneously flash about once a day. If the flashing is frequent, there may be a problem. The fish is itching and attempting to scratch itself. The most common cause of this behaviour is parasites. Other causes can be a sudden change in water conditions or the presence of a toxin.

Spiralling, swimming in tight circles
This type of behaviour normally indicates that there is either neurological dysfunction, internal parasites or damage to the inner ear/lateral line of the fish.

Swimming upside down, on one side or buoyancy problems.
The most common cause of this behaviour is swim bladder disease. This can either be inflammation, infected by bacteria or fungus or filled with water. Another reason for this behaviour may be advanced Trichodina infection.

Top swimming
This is mainly an indication of respiratory problems caused by parasites or a bacterial infection.

Last Updated on Saturday, 19 September 2009 21:30