Treating your Koi Fish Illnesses

Ranging from parasites to fungus, bacteria to viruses, there are numerous illnesses and health issues that can affect your koi (the more common of which we looked at in a recent post). In this article, we look at some of the more general and commonly accepted types of treatments used against koi fish illnesses.

Increased Salinity

Salt is often the first line of defense. Higher concentrations and dips are helpful in reintroducing electrolytes to newly shipped koi, strip the slime coat and knock off parasites, while lower concentrations will stimulate slime coat production which increases antibody protection to combat parasites.

Additionally, even if the salt is not directly helpful, it can calm a stressed koi, reducing the opportunity for further infections. It also reduces water intake through the osmoregulatory system thereby slowing any new pathogens entering the koi’s system.

There are salt-resistant parasites (like costia and trichodina) emerging due to oversalting; however, newer brands of Malachite Green and formalin blends (like Terminate) are proving effective against these resistant strains of koi fish illnesses.

Higher Temperature

Generally speaking, koi pathogens don’t survive in higher water temperature. Higher water temperatures can also be used to speed up the immune system of cold-blooded koi, thereby helping with the healing process.

Quarantine

Many of these koi fish illnesses are communicable. Even though koi can often coexist with those pathogens that cause illness, once the illness is discovered, the infected fish should be isolated and quarantined from the pond and other fish to minimize the possibility of passing it onto other fish in the pond.

Once the koi is in it’s own tank (or tub), treatment protocols can be started. A smaller space makes administering the particular treatment easier to accomplish and monitor.

There are instances when salt, heat and isolation will not get the job done and other medicated treatments become necessary in conjunction with these protocols. Like most medicines, there are numerous commercially available products, and recommendations for the most effective treatment types and brands will vary; but here are some widely accepted types of treatments used to combat different types of koi fish illnesses.

Parasites

There are often parasite-specific medications (like praziquantel for flukes). Potassium permanganate can be a good option, too, but the general go-to option is the malachite green and formalin. Amounts and concentrations might vary according to the practitioner. Utilizing gloves is recommended.

Visible parasites (like anchor worms and fish lice) will have to be removed with tweezers after sedating your koi. Some enthusiasts recommend applying Neosporin to the wounds as well as adding Dimlin to the water over a period of three days.

Bacteria

Topical sores from bacterial infections can be treated with a hydrogen peroxide-soaked q-tip followed by the application of a medicated antibacterial cream. Potassium permanganate can also be applied to the wounds.

You can opt for antibiotic food; however, it has to be ingested to work and sicker koi might lack the desire to eat it. Injectable antibiotics (like Baytril to name one) are probably the most effective way of dealing with bacterial infections.

Fungus

In a similar fashion to bacteria, fungal treatments can be treated with cotton wool (for removal) and then by applying antimicrobial cream (like propolis) to the infected area.  Salt baths, malachite green (a fungicide) and/or another anti-fungal product are also viable options.

Important note: sometimes the illness can be as simple as a pH imbalance or high nitrite levels. If you are ever in doubt as to the nature of your koi fish illnesses, it is always best to consult an expert, as this will inform your treatment choice. The incorrect treatment can do more harm than good.

At Next Day Koi, we source our fish from some of the biggest and best koi farms in the world. All of our koi are quarantined for a minimum of two weeks before being listed for sale and are monitored closely for any signs of health problems during that time. If any health problems become apparent during quarantine, the affected koi are treated accordingly.