White spots on koi or goldfish are some of the most common diseases. It’s important to figure out whether the particular disease your fish has is parasitic or viral, as viral diseases cannot be cured with any medication. Once your fish has been infected, it will carry the virus for life. Parasites, on the other hand, can be eradicated with the proper treatment. Here’s a look at 3 common white spot pond fish illnesses: Ich: (parasitic) This is one of the most common fish diseases around. Luckily, if you catch it quickly it is very easy to eradicate and does no harm to the fish. If left untreated, however, it has devastating effects and can lead to death. Ich is also highly contagious, and spreads easily and quickly to other fish. Ich looks like tiny white dots all over your fish as if someone has sprinkled small grains of salt all over it. Ich parasites have a lifecycle of about 10 days, so it’s important to keep your treatment going for at least that length of time, since it’s impossible to tell what stage of the parasites lifecycle you have caught it in. You may notice your fish rubbing against surfaces in an attempt to scratch. The fish may swim funny or look lethargic. Salt and warm water does a good job of curing Ich, but there are also innumerable commercial meds addressing this issue as well. My personal favorite is quICK Cure, available at many local fish shops. It typically stops Ich in 24-48 hours Pox: (viral) This disease is obvious because the white spots look like candle wax drippings on the fish. They are most common on the top part of the fish, particularly on the top of the head—but can appear anywhere. Pox is most commonly spotted in the spring and warmer months, and will usually appear to “cure” in colder temps. The fish, however, is not cured at all as the disease is viral. Sometimes, you will see carp pox just one summer and it never returns again; in other cases, the disease will show itself each spring when the water warms up again. Being a virus, there is no cure and the fish simply lives with the disease for the rest of its life. It rarely kills a fish, but is usually only disfiguring with the candle wax spots. Pox is usually brought into a pond because a new fish that has been exposed and was not properly quarantined has been introduced into your pond. Once that fish is in your pond, all your fish are now exposed. They may never exhibit the white spots, but they are carriers nonetheless. Any fry born, are also natural carriers. The only way to eradicate pox from your pond, is to completely destroy the herd, clean the pond with a light bleach solution, throw out your filter materials and start up a fresh pond. Truly, however, fish can live perfect lifespans with pox, it is just important never to give away any of your fish or plants to another pond keeper, as you will pass the disease onto their pond. Lymphocystis (viral): This virus shows itself as large bumps that look like rice grains or rock salt. Sometimes, the bumps knit closely together and appear like a small head of cauliflower (which is why it is sometimes called “cauliflower disease”). It can look white, slightly pink or even cream colored. Sometimes the disease attacks the fins or tail tube only, and other times it spreads all over the fish. Like Pox, this disease rarely kills a fish, and the fish can live normally. Sometimes, however, the bumps can cover the mouth area, which makes it hard for the fish to eat and it will die. Additionally, there is liability with Lymphocystis of death not because of the disease itself, but because the fish’s immune system is compromised, it is open to secondary infections that can cause death. Therefore, it is important to ensure a highly clean pond to prevent other parasites from invading. This disease is viral just like Pox (see above), and holds the same caveat in that it is not curable and all your fish are technically exposed. Do not give away any fish or plants from a pond infected with Lympho! Like pox, the disease can regress and you may see no trace of the spots after a time, but the fish will always be infected. There is some claim that quICK Cure "cures" lymphocystis with a two-week round of use. There is no definitive study on this, but some people swear it is the case. Even if your fish appears to have been mended, you should still assume it is a carrier.