Definition

• White-Spot Disease is a communicable disease that affects the gills and skin of fish. It is characterized by small white spots that cause skin irritation and, in severe cases, may inhibit breathing and cause death.
  
  

Symptoms

• White-Spot Disease is easily identified by the white spots that appear on a fish's body and gills. These spots will grow to sizes of about 0.5 to 2.0 mm and may appear on a fish's fins first. Fish may swim with their fins clamped to their sides if their fins are affected. In severe cases, fish exhibit loss of appetite, lethargy and respiratory distress.
  
  

Cause

• White-Spot Disease is caused by a protozoan called Cryptocaryon irritans, a microorganism that naturally lives on the skin and gills. In aquariums, fish are often stressed from handling, leading to compromised immune systems. Additionally, there is less room in an aquarium than in the wild, so Cryptocaryon populations tend to be denser on captive fish. These factors make it easier for Cryptocaryon to penetrate a fish's natural defenses and establish itself as an infection.
  
  

Treatment

• There are multiple treatments available for White-Spot Disease. The first and most drastic is to use one of the many copper treatment kits available for home aquarium use. Copper is lethal to the protozoa responsible for White-Spot Disease, but it is important that it be used in the correct dosage as it can poison your fish as well. Other treatments involve UV sterilizers and diatom filters, which keep the population of protozoa at manageable levels for your fish.
  
  

Prevention

• Stress is the number-one cause of White-Spot Disease. Ensure that your fish are well cared for by maintaining a clean tank and providing them with adequate food and shelter. When introducing a new fish to your aquarium, consider quarantining the fish until it has acclimated, as new fish are often stressed and may bring infection in with them.