Fish Diseases:  ICH or White Spot

Triggered by a deep-burrowing parasite, ICH--also called white spot--is a highly contagious and all-too-common disease that causes small white pustules on a fish's skin and gills. Affected animals may rub themselves against objects in the tank in an effort to stop the uncomfortable itchiness. Treatment involves isolation of the sick fish and medication.

Identifying Ich

White spot cysts, each containing an active trophont, appear as small white nodules on the skin, gills and fins, giving the fish the appearance of having been dusted with salt. In a confirmatory skin scrape the trophonts appear as dark round objects slowly rolling around. The trophonts vary in size, up to 1mm and are considerably bigger than most fish parasites. Other features sometimes seen are a lighter, horseshoe shaped nucleus and short cilia covering the entire body.

In the early stages of the disease, fish are likely to flash and rub against objects because of the irritation. At a later, advanced stage they will become lethargic and spend most of their time sitting on the bottom.

Ich commonly affects koi - but in the early stages the characteristic white spots are very difficult to spot. They are probably there but not very noticeable. This is one reason why it is best to do a skin scrape when parasites are suspected - so that you know exactly what you are dealing with! Even finding one trophont warrants immediate treatment.

Treatments

Ick Guard (Crystal) Also guards against secondary infections as a result of wounds left by the ick parasite. No need to raise the water temperature. Use Ick Guard II on small, weak or scaleless fish.

Quick-Cure Aquarium Ick Cure 3/4 oz. Quick Cure is an scientific formulation utilizing special zinc-free ingredients which cures ick in only 2 days. Quick Cure is safe for Freshwater and Marine aquariums (though it should not be used with invertebrates).

Ick Clear Tank Buddies - 8 tablets Quickly clears ick and protects against secondary infections. No need to raise the water temperature. The fizz lets you know it's working! One treatment is usually all it takes. No need to raise the water temperature.

Beware ICH can lurk in the background

Ich is most often brought into the tank or pond on new fish or plants. However, it is also believed that some survivors of an Ich infection can become latent carriers, with the parasites forming a latent stage at protected sites such as the base of fins or the gills. 

Subsequent stress or poor conditions can awaken white spot to re-infect either its host or other fish. This certainly seems to be the case with koi, when often small numbers of trophonts are often found alongside severe fluke, Trichodina or Costia infestations, even in ponds which have not had any new introductions.

• Fungus, Algae, Bacteria & Ick Control - Aquariums