Common Koi and Goldfish Medications Used to Treat Diseases in Ponds

Since most medications that target bacteria, fungi or parasite are toxic to koi and goldfish and filter bacteria it is of paramount importance to follow instructions carefully and this means knowing your pond volume quite accurately. Click here for calculator that can be used to find the volume of any pond no matter what the shape is.

Remember underdosing stresses the fish without resolving the disease problem.

What Type of Diseases Exist in a Koi or Goldfish Pond?

There are 4 categories of disease causing pathogen namely: viruses, bacteria, fungi and parasites.

1. Viruses are responsible for diseases such as carp pox , SVC (spring viremia of carp) and recently KHV (Koi herpes virus which is a viral disease highly contagious to koi). Viral diseases are not able to be treated with medications and cure relies upon a koi or goldfish having a sufficiently strong immune system to recover. This is why sensible feeding of koi and goldfish during winter is a good idea.

2. Bacterial diseases notably fin rot, gill rot and ulcers are caused by specific bacteria that can be treated in and out of pond using chemical agents and antibiotics. Ulcer disease problems can be controlled by eradicating levels of Aeromonas in a pond using Viresco or Koizyme.

3. Fugal disease appear as cotton wool on damaged body parts caused by scraping or ulcers for example. Fungal diseases are difficult to treat because the fleshy interior of the fish as well as the external surface is effected. Fungal disease are not contagious. Fungal spores exist in all ponds

4. Parasitic diseases include Chilodinella, Trichodina for which a microscope is required to diagnose and those visible to the naked eye including Fish Louse, Anchor Worm, and White Spot. They attack the exterior and interior of koi and goldfish and grow to several cms in length.

Parasites on wild fish remain in a finely balanced relationship where their level of infection does not cause the death of the host. It is in the parasite's interests to keep its host alive. In captivity in a koi pond, however, koi and parasite relationships can become unbalanced causing the death of the host. Treatments for parasites vary according to the location of the parasite (internally/externally), the size of the parasite and its lifecycle.

What treatments are used in koi and goldfish ponds?

Malachite green, formalin, acriflavine, potassium permanganate, methylene blue, antibiotics and salt are the main chemicals added to ponds to control or cure disease and restore fish health.

Malachite Green

Malachite Green is a dye used to treat fungus and microscopic parasite infections such as Chilodinella, Costia and White Spot. Malachite Green is a wide spectrum medicine. It is toxic to both humans and fish when used incorrectly. It is often used in conjunction with formalin. When Malchite Green and Formalin are used together it is the recommended treatment for white spot or Ich.

For an excellent discussion on Malachite Green and Formalin see http://www.fishdoc.co.uk/treatments/malachite.htm

Formalin

Formalin is a solution of formaldehyde gas diluted to a strength between 37% to 40%. Formalin is toxic and needs to be handled carefully. Formalin is a disinfectant. It works by destroying cell proteins in the offending parasites. It is important that dosage levels are calculated correctly. Formalin is often best used in conjunction with Malachite Green.

Acriflavine

Acriflavine is a yellow powder with disinfectant properties and it easily dissolves in water. In people it is used to treat mouth and throat infections and for cleaning wounds.

Acriflavine is efffective against external parasites in fish ponds. Acraflavine is effective as a fungicide, against Saproglenia ssp. Acriflavine is also effective against protozoans such as Ambiphyra, Chilodonella, Cryptocaryon Irritans, Hexamita, Ichthyophthirius multifilis, Oodinium and Schyphidia species.

Potassium Permanganate

This is a dark purple water soluble crystal effective against bacteria and external parasitic infections. Most people are familiar with this chemical as a mouth wash at the dentist. Potassium Permanganate is used to disinfect fish before adding them into a new environment such as those koi that are imported. It is then used as a dip. Getting the dosage right is vital since over-dosing is toxic to fish. Potassium Permanganate is a strong oxidising agent and reacts with organic matter in the pond reducing its efficacy.

Potassium permanganate acts against a range of protozoan parasites including Trichodina, Costia and Chilodonella, as well as monogenean flukes Gyrodactylus (skin flukes) and Dactylogyrus (gill flukes). In addition to its use as an anti-parasite treatment, potassium permanganate helps clear up bacterial gill disease and other bacterial disease such as skin ulcers.

Methylene Blue

Methylene blue before dissolving in water is a dark green powder. After dissolution it turns blue. This chemical is used against bacterial, fungal and parasite infections. It will kill plants and pond biofilter bacteria.

Antibiotics

Antibiotics use is normally controlled by prescription to prevent indiscriminate use that can result in bacterial resistance.

Antibiotics can be added to pond water, used in out of pond dips. Antibiotics can also be injected at the sites of the ulcer for example or also fed in food. If added to a pond the bacteria in the biofilter will also be killed.

When bacterial treatment is required it is best to engage the services of a vet familiar with fish diseases and treatment.

Salt

Salt (sodium chloride) is used by many koi keepers in order to prevent certain infections within the pond or to treat infections.

Many koi keepers attribute salt to having many benefits as far as their koi are concerned. They know that salt has an effect upon parasites and can be used as treatment for parasite attack in an out of pond bath. Salt is also known to be effective in the promotion of healing.

Many koi keepers will maintain a low level of salt in their pond on an ongoing basis while other koi keepers use low concentrations while over-wintering their fish. During winter koi become stressed to a certain degree and by applying salt in pond water at 0.3% level the eflux of salts out from the koi's body is reduced which helps to relieve this stress to some extent.

Most disease problems are the result of poor water quality problem. By making sure you have a well sized biofilter and keeping it running then most ponds will avoid health problems.

Please also check out this UK Pond Doctor site