Carp pox?

A recent reader asked about carp pox in koi/goldfish. While there are several viruses that affect fish, 3 are well-known. The most common viral disease is Carp Pox. In koi, it causes epidermal hyperplasia (swelling) and results in papillomatous white to gray plaques on fins and skin that is often described as "candle wax" in appearance. The lumps can be scrapped away, but the removed material is infectious. Carp pox is generally seen in the cooler water temps during the winter and spring when fish are generally stressed. As the water warms, it usually will regress. After regression, the viral genome has been found in spinal nerves, cranial nerves, and subcutaneous tissue. I compare this to humans and shingles or even cold sores. Shingles is a viral disease that comes from chicken pox. The sleeping virus sits in our lower back and under stress can erupt as shingles in humans. Cold sores are a type of herpes virus just like carp pox. It lies harmlessly in our bodies and in our fish until stress causes it to reemerge. In fish it is usually an environmental stimuli. Cold water, overcrowding, poor water quality, etc. There is no known cure for viruses. Specific treatment is typically not required;improvement in environmental conditions and removal of underlying stressors typically results in spontaneous resolution. The condition is generally not life threatening to the fish carrier itself. However, the catch 22 is, if left in the pond with other fish it can be transmitted to them. "Usually", initially you may see one fish with it, then next year 2, and then more. Again, it is not life threatening to the fish, but can be unsightly. If fish are healthy and happy they may never display symptoms, as it is thought to be stress related. Also, keep in mind that if you see one fish with it in your pond, then it is probably too late as all fish have probably been at least exposed to the virus, even if they don't show symptoms. Personally, I have seen it in many ponds and even my own. In my own pond,I pulled the fish and put it to sleep. I have seen no further recurrence in my fish.
There are 2 other common skin conditions in fish, and I'll address them in the next 2 post.
ATTENTION: Please don't handle sick fish with your bare hands, always use gloves. Many fish diseases are infections to people too!!