Lymphocystis
This is a common viral disease (herpes) that affects both freshwater and saltwater fish. It is noticed by aquaraists when their fish have become stressed, and was thought to have started through invasion of external damage. However, it has now been discovered that it enters the body as a spore taken in through the gills or injested. It can occur in the best kept koi ponds and does not depend on water quality or fish health.
The first signs are small, white pin-prick looking growths that occur on their fins and skin and at this early stage can be mistaken for Ich/Ick (Ichthyophthirius multifiliis). However, it soon clumps together and forms a cauliflower-like growth on the skin, fins and occasionally the gills.
Currently there is no known treatment for this virus and eventually the growths will inhibit the fish's ability to swim, breathe and eat. Secondary bacterial infections are a general result of this virus and without proper care, will usually kill the fish.
A specialised fish vet may recommend surgery to remove the affected area when it becomes very serious.
The best attempt at a cure is to give the fish a stress-free life, a weekly bacterial treatment such as Acriflavin, which will prevent seconadary infections and give the fish some chance at recovery, although this may take several months. In some cases the virus gradually subsides and the fins may repair themselves, the general outlook will depend on whereabouts on the body the growths occur and to what severity they are noticed.
