PondBiz Blog: Fish Health and Parasites

Koi fish are prized for their loveliness and ability to bring a pond to life! However, because they have been selectively bred for beauty and not strength, koi tend to be somewhat prone to parasitic attack. Fish parasites are all microscopic organisms that live inside the fish and gradually cause a myriad of health problems that can prove fatal, if left untreated.

Causes: Most parasites are brought in by other fish, which is why we highly recommend that you quarantine new fish before introducing them into your pond for at least 3 weeks. During this time, the new koi should be treated for parasites. Just quarantine alone is no assurance that your fish are parasite-free. New fish should be given parasite medicine, regardless, to prevent infecting your other fish. Some parasites can live in ponds for a long time, before becoming an issue, so it can be difficult to trace the origins. However, it is most likely caused by new fish.

Signs: There are many different parasites that can plague koi, such as flukes, costia, ich and anchor worms. However most parasites are microscopic so to find out which parasite you might have, you will need to use a microscope. Without a microscope, you can look for certain signs that some type of parasite is present:

  • one fish isolating itself from the other fish
  • flashing (when a fish swims near the side or bottom of the pond and then quickly swims off by first rubbing its side against the pond wall.)
  • one or more fish have stopped eating
  • one fish is spending much of the time near the waterfall, gasping for air.
  • fish have visible sores on their scales
  • fish are dying

Ich causes white spots on fish while Trichodina is noticeable in fish that flash, flick and have an excess of mucus. Chilodonella is a fast killer; inected fish will appear lethargic and may be resting on their sides. Anchor worms and fish lice are a bit bigger and will attach and feed on the scales of fish. All of these must be treated immediately upon discovery to minimize harmful affects!

Parasite treatment: Treatment should be administered as soon as you discover the issue. Take the stress level of your fish into consideration and try to keep that at a minimum, when administering treatment. Please follow all packing directions carefully to make sure you are giving fish the proper dosage. Too strong a dose will further harm your Koi! We recommend the following products:

  • Microbe-lift Parasite Treatment (ICH-OUT): promotes rapid relief of Ich and parasitic diseases for all pond fish. It combines three of the most preferred anti-parasitic ingredients as well as a topical treatment for an effective healing from Ich (white spots) Trichodina (flicking, flashing, excess mucus production) and Chilodonella.
  • MinnFinn: a revolutionary new product that controls virtually all external pathogens impacting Koi health. It has been found to be extremely effective against Costia, Trichodina, Columnaris, ICH, Flukes as well as most other bacterial, protozoal and fungal infections.
  • Prazi Pro: the first ready-to-use liquid concentrate Praziquantel treatment. It is the most effective treatment available for control of unwanted parasites; flukes, tapeworms, flatworms and turbellarians.

For a full list of products that boost fish health, please click here.

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