Koi Disease – Dealing with Parasites
Parasites are a common problem for all fish. Koi fish are no different. When you think of parasites with Koi fish you generally will be dealing with the external variety. These types of parasites are always present in the water and are easily passed from one fish to another. In the warmer weather, the parasites are more active and visible. In the colder months the parasites remain inactive and more difficult to detect. Koi disease resulting from parasites should be delt with quickly.
What’s the real problem with parasitic infestation? Well the obvious answer is the damage to the fish as a result of the parasites feeding on blood and skin tissue. But perhaps an even more dangerous result is creating a condition in your fish that makes secondary bacterial infections and othe Koi disease more likely. If parasites do become a problem for your fish, a salt treatment will generally kill most of them. Occasionally other steps will be needed, but always try the easy steps first.
The anchor worm is a common parasite that attacks Koi usually around the gills, eyes, on the fins, and around the base of the fins. The location where the anchor worm attaches itself is usually inflamed and the scales in the area are sometimes raised a little from their normal position. Anchor worms are not active during the winter months, but when the water temperature gets in to the upper 50s they will rapidly appear. Adult anchor worms are about ¼ to ½ in. in length and can be pulled off with tweezers. However this is a time consuming job. A better approach is to add a medication treatment to the pond water to eliminate the problem.
The Apiosoma parasite is another pest that is too small to be easily seen with the naked eye. Usually it is better to be aware of the systems that include:
- Heavy mucous
- Clamped fins
- Troubled respiration
- Head flicking
- Loss of appetite
- A big head – due to the loss of weight the Koi’s head seems to be out of proportion.
There are several treatments for this ailment that include adding salt to the pond, salt baths for the fish or adding a commercial anti-parasite to the pond. Again, Apiosoma can lead to other Koi disease if not treated properly.
Chilondonella is another Koi disease (parasite) to be on the lookout for. It is also difficult to see without examining a scraping under a microscope. It’s best to be watchful for telltale symptoms of this parasite. There several symptoms that can indicate Chilondonella. The Koi may become lethargic and remain near the filter outlets because their gills are affected and aren’t functioning well. Their skin may become covered with a grayish film and there may be respiratory distress. The best treatment for this is usually salt or Potassium permanganate in the pond.
The Costia parasite is most likely only going to be seen under a microscope. It will attach itself to the Koi’s skin and gills, feeding on the tissue. If your fish are infected by Costia they will not feed, become lethargic and gasp for air. Often there will be an excessive mucus excretion. Costia is best eliminated by treating the pond with potassium permanganate available at most pond stores.
Argulus (fish lice) are similar to anchor worms. They look like small dots of clear jelly. They pierce the Koi’s skin to enable feeding. They inject an anticoagulant to help them feed. This anticoagulant has a toxic effect on the fish and can be fatal to small Koi. Adult fish lice are large enough to be seen with the naked eye. The lice can get into the pond from plants brought into the pond or fish already infected. Treating the pond as you would for Anchor worms is the easiest way to get rid of the lice.
Body and gill Flukes are very common on Koi and usually don’t cause a problem unless the fish is weakened by another Koi disease. The treatment for flukes is again potassium permanganate. If the infestation is severe and several fish are infected, you will probably want to use Fluke Tabs - a medication available at most pet stores - designed specifically for treating Flukes.
Ich or white spots appear as little white spots on the Koi’s skin. They usually appear when the fish experience a sudden temperature drop. Ich is very contagious and has two life stages: nonswimming stage on the fish and the free-swimming stage. They can only be controlled in the free-swimming stage. There are several very effective commercial anti-ich treatments available.
Parasites like other Koi disease, can be nasty and a real bother. Watch your fish closely especially in the warmer months. If parasites are suspected take action quickly to protect the health of all your Koi fish.
