As a responsible Koi pond owner you will want to make sure to protect your fish from both bacterial and fungal Koi disease. The best way to do this is to do a daily visual check of each fish. Feeding time offers the best opportunities to notice if anything appears to be “off” with how your Koi look and/or act.
First I will review how to recognize and treat some commonly found bacterial forms of Koi disease.
Bacterial Hemorrhagic Septicemia symptoms include red streaks on the fins and body or redness in the body itself. Your fish may also have open sores and/or loss of scales. For treatment you should use an antibiotic Koi disease medicine or oxytetracycline in feed or a fungicide/protozoacide dip/bath treatment in the water.
Open red sores or ulcerations and fin and/or tail damage (they can sometimes be completely eaten away) are indicative of Pseudomonas bacteria. Again, use an antibiotic Koi disease medicine or neomycin or kanamycin in your feed and a fungicide/protozoacide dip/bath in the water.
FlexiBacteria, which causes Columnaris disease, is indicated when a fuzzy, thin, white coating appears on the body and fins. It resembles a fungus. For treatment use sulfathiazole sodium.
Piscine Tuberculosis is a bacteria that must be treated with great care as it may spread to humans. Some signs of Piscine tuberculosis are; your fish has been sick for several months, is lethargic, anorexic, shows scale or fin loss and has a distended stomach. You need to treat this Koi disease with kanamycin and Vitamin B6 for at least 30 days.
Furunculosis is another bacterial disease you should keep an eye out for. One or more fish will have blisters forming on their skin that are full of a clear or yellowish fluid. These blisters will pop and become large open sores. These fish need to be treated with Furzolidone pwder for 10 -14 days.
Now we will take a look at some of the more common fungal disorders that are considered a Koi disease.
If your fish get Water Mold Infection they will look like they have green algae growing on them. Effective forms of treatment are either using Erythromycin for 10 days or a fungicide/protozoacide dip/bath treatment in the water.
Symptoms shown by fish withSaprolegnia Fungus are white, cottony puffs on their skin and gills that will turn into open, red sores within 24 hours. For this Koi disease you will want to treat with Copper Sulfate.
When fish contract Branchiomycosis they appear to be weak and lethargic and they gasp for air. Some fish lag behind the school in the pond. This is a very serious Koi disease and a large amount of deaths can occur in your pond. Make sure to treat all fish with a fungicide/protozoacide dip/bath treatment in the water. It is also important to make sure you’re not overcrowding your fish and are keeping your water quality high.
With all of these fungal disorders it is very important to keep your pond water filtered, free of overcrowding and free of surplus organic material. In fact, these measures are not only important for these fungal disorders, but for any Koi disease.