Unusual Skin Growths (at least to me)

[Steve E.]

I have a friend who has a 15+ year old concrete pond.  Gravel filters.  Water temp varies between 48 and 50 at this time.  Water is clear, but with moderate algae growth on the bottom.  Good moderate length algae growth on the walls.  Two of his largest fish, 30 inch overall longfin, and a 30 inch koi have developed some strange growths on their skin and one leading edge of a fin.  These growths are tanish in color, raised slightly, wrinkled appearance, range from circular the size of a quarter to oblong about 1.5 inches by .5 to .75.  They have been stable this way for at least a month.  All fish appear to be moving normally for the water temps, no flashing, no laying over, no breathing issues such as gulping air at the surface or in the waterfall outflows.  Trying to minimize handling stress, I have not bowled either fish at this time due to their size and not having any idea at all what could be causing these growths.

Before I bowl them, I would like to have some idea of what may be causing the growths.  I have several good reference books, but do not where to start looking.

Steve

[KoiCop]

Hello Steve & Welcome to KoiVet . . .

Pix would be essential to doing anything more than shooting in the dark, but here goes . . .

The pathogens we usually deal with are parasitic, bacterial and fungal; in all likelihood, we can probably rule these out.

Then there are viral infections, such as Lymphocystis, which might be what you've described.  If so, Lympho (while disfiguring) is not fatal.

And, finally, there are any number of various and sundry skin conditions (up to and including tumors) which might be what you've encountered.

In any case, definitive answers will require taking biopsies and having them analyzed by qualified personnel.

Best wishes,

[captk]

Hi Steve,

Don is spot on. Pics will tell a better story. It does sounds a little like lympho too but that is just a stab in the dark at the moment.

[KoiCop]

Hello Steve . . .

I should have added that you can do a Google search with the following parameters to locate and compare photos:

koi photo lymphocystis

Best wishes,

[Steve E.]

Finally found the weather and time to take some photos.  I picked three that seem to show the growths the best.  In Photo 1 of the mostly head shot the growth shows a dark spot in the center.  We dabbed at this growth with a soft cotton towel, the outer surface pealed away at a light touch, and there was some discharge of a dark pale red/purple nature on the towel.  No flowing discharge as if it were coming from a pocket.  The interesting thing is the location of these growths is not limited to one pattern color.  Nor to the body in general, but can be seen on the leading edge of fins.  I checked the several online references from above and did not find any pictures that looked similar to these growths.  None of my text books show this either.  Now it is very possible (probable) that I just did not see a similar growth picture in those references but I hope I was paying attention.  I will have to post the photos in three different posts due to file size limitations.

Steve

[Steve E.]

photo 1

[Steve E.]

photo 2

[Steve E.]

photo 3

[KoiCop]

Hello Steve . . .

Thanks for putting up those high quality pix.  Great job and very helpful.

Would appear to be hikui (that's the Japanese term for what they thought was a red-eating worm).

Nowadays, it's considered to be a virus, a rickettsia or skin cancer.  Treatment is iffy (at best) and while it's disfiguring it's not fatal.

Here's a great explanation from JR.

Hikkui

JR 1 May 2007
http://www.koi-bito.com/forum/general-koi-forum/6168-koi-skin-problems.html

Yes, that is hikkui. The problem is no one really knows what hikkui is. And in all likelihood we are calling the 'symptom’ we see hikkui when it is probably a look that is given by several different causes.

In winter you can see several skin conditions from clouds/patches of fish mucous 'lifting' from the body. This will resolve itself on it's own once the fish is in warm water again and producing slime coat and moving (the act of moving sheds slime coat into the water). If the fish is depressed however, this same white gray patch can be a sign of parasites (especially if red veining on the white skin is also noticed). The area should be scraped and examined under a microscope (under low light/high power) for costia or Chilodonella).

If the lesion is white or gray and raised (as if candle wax was dripped onto the body then you are looking at koi herpes (carp pox). This is a seasonal thing as the virus gets active and then goes dormant based on the stress (usually due to cold, but can be due to poor water conditions) and rebound of the fish's immune system which suppresses the virus. There is no treatment although a few hobbyists are experimenting with injectable virus meds.

Koi also get small tumors, fatty tumors and warts. And these can be red, orange, colorless and tan. Harmless but unsightly, they usually come in single lesions and once in a while in rows or patterns (again a virus).

Finally we have hikkui. Once thought to be 'hi eating worm', it is now considered a virus, a rickettsia or skin cancer. And in fact different cases may be any one of these suspects.

It is a disease but it can be triggered by environmental causes. So I have seen a pond full of hikkui fish and I have seen a hikkui free pond with one fish that develops hikkui and one fish only. It is also age related with older fish showing more lesions that younger fish do. The immune system is definitely involved as well and returning a koi to 'mud' will often suppress the disease but only for a while.

I have removed hikkui and warts with cryosurgery with good success but the fish is disfigured to some degree as a result of the treatment. And some have has early success (must be early before the disease has destroyed dermis and epidermis) with billion liquid. The hair dryer is used with the liquid after the fish has been removed from the bowl and the area is cleaned and billion liquid applied. This dries out the liquid compound and adheres it to the cells. Another treatment is to place the fish in warm water (85 F) and manipulate KH. This is reported to be successful in 90% of early cases. This suggests a virus. But again, I believe that people are diagnosing a complex of diseases as hikkui so some things work for some, based on what it is- skin tumor, virus, rickettsia, skin infection, genetic weakness etc, and not for others.

Here is a shot of an advanced case. JR

Follow this link to Duncan Griffiths' website in England for pix and treatment protocols:

http://www.koiquest.co.uk/Hikui.htm

Hope this helps, Steve.  Any questions, fire away, OK?

Best wishes,

[Steve E.]

That is what I was leaning towards, but since neither of these fish are gosanke I was not really sure.  I did not mention my thoughts to avoid prejudicing anyone's thoughts on what they were looking at.  The other fish is a longfin, both are over 10 years old and in the 26 inch range.  I did discuss the possibility of hiqui with the owner and he will probably elect not to treat.  Thanks for everyone's time.

Steve