I'm not a koi person, so I turned to Google. It sounds like a lot of things can cause sores in pond fish. There is a chance it's an infection and if so you would need to use antibiotics.
Scroll down to the bottom of this page for a list of things that sometimes cause open sores in pond fish. Bob's page reads as if the sores are not always infected and you clean the pond and filters, use salt, and add something like NovAqua to help the slimecoat. If they're healing this might be a prudent course of action. http://www.wetwebmedia.com/pondsubwebindex/pdfshdisart.htm I also turned this up in Google as an approach for infected ulcers. You give the fish a medicated food (or an antibiotic injection if it's a valuable enough koi to enlist the services of a vet), and check over all the fish and the pond to see if there is an underlying cause that has weakened the fish. http://www.goldfishconnection.com/articles/details.php?articleId=178&parentId=23 Hope this helps, and maybe someone who knows more about koi will stop by. Altum On May 24, 7:17 am, Philip <[email protected]> wrote: > Hi Group! > > I was wondering if anyone would be able to help me. I have a large Koi > that has developed several wounds on its head ringed in white. They > appeared suddenly on monday and are looking slightly less raw today I > think (but I could be wrong). > > I have a picture here:http://tinypic.com/r/2mm7954/7 > > The picture isn't the best, it's actually quite a bit worse than that, > confined to the head. It's mostly on side of the fish at the top and > to the back of the head. > > I was wondering if anyone in the group might know what it is and what > treatment is required. > > All the other fish in the pond appear normal. I have tested the water > with a 5 in 1 test strip which put the pH, GH and KH hardness Nitrate > and Nitrite within normal bounds. > > Philip
