Pink Lesions on Koi - Help

[Richard Rombold]

Quote: Originally Posted by JasPR good call, that may be a possibility. Hard to know without a scraping. In a lot of these protozoa, the slime coat dies and lifts, leaving a very general symptom of a 'patch' of white/gray/pink or yellow. The lesion on the tail also looks like Dermocystidium, another imflamatory reaction within the skin. Rather than a protozoa these fungal hyphae live within the cyst. Again, can't really tell from a photo, but if the growth is removed and examined, it will be filled with spores and strands of hyphae. Or, this all could just be hyperplasia caused by herpes virus- IE carp pox JR

JR, I agree that we are just guessing here. A sample would need to be viewed microscopically to be certain.

The "patch" is not the residual effect of the slime coat being disturbed, but rather the colony itself, and becomes raised and quite pronounced. It is rubbery to the touch and cohesive. The protozoan use the host as an attachment site from which to feed. Outbreaks are triggered by high organic loads. I would not rule out fungus, but fungus feeds off host tissue and we don't see that here. Finally, carp pox is actual tissue that was mutated by a virus. This tissue is vascularized and if removed will bleed and scar. It's just deductive reasoning and a guess, but I don't see that we are left with many other culprits than some form of sessile, colonial protozoan when you look at what we know. It's a good discussion because I believe this is widespread and usually misdiagnosed.

Richard

[KoiCop]

Very interesting, Richard.

So if I've got it right, then, when scraping reveals there are no blood vessels in the blob it's not carp pox?

[Richard Rombold]

Quote: Originally Posted by KoiCop Very interesting, Richard. So if I've got it right, then, when scraping reveals there are no blood vessels in the blob it's not carp pox?

Koi Cop

Viruses mutate cells by hijacking their DNA. The virus is within the cell. When you see the boil on carp pox you are seeing mutated fish tissue. This tissue is supplied with nutrients through a network of vessels and capillaries just like any other vertebrate tissue. Put it this way, if you cut off a wart what happens?

Richard