Koi developing ulcers and potential blister? Help!

[Firsttimekoidad]

Hi all. I'm a first time koi owner (and first time poster, so please excuse any formatting errors) who got some fish for his pond earlier this year. Everything has been going well, but in the last two weeks, one of my fish started developing sores and popped eyes. It has also been exhibiting flashing and trying to rub itself on the bottom of the pond occasionally.

PH is between 8-9, ammonia is 0, and nitrite is 0, before any water change. Pond is about 1,000 gallons and has 5 koi that are about 4-5 inches big.

I have tried to treat it with and ulcer and bacteria treatment by Aquascape I bought at my local pond store, which had a 3 does every other day routine, followed by a 25% water change. The fish is still developing red spots around the initial spot on its back, and some around its mouth. It has gotten more timid, and although it has been eating all week, now spits up its food immediately. Today, when I came out to do the water change, I also noticed a large bubble-like blister had formed on it's back left side. You can see this blister in two of the photos I'm attaching. Then, after the fish flashed a few times, the blister disappeared. I'm assuming it popped it.

I'm a little stumped as to what could be going on. The water quality seems to be okay, the other fish haven't shown any symptoms of anything yet. The pond store guy told me over the phone it sounds like dropsy, but I haven't noticed any raised scales, and the water quality seems fine. We have a large marsh down the hill behind our house and lots of small frogs frequent our pond. I'm wondering if the fish's health could be compromised because of a parasite, since the bacterial treatment appears to have not done anything, and because of the flashing behavior.

After the water change today, I introduced some API Stress Coat, but I haven't started any other treatments because I'm trying to decide what to try next.

I don't have the equipment or skills to do any scraping and micro-scoping. I have some Microbe-Lift Broad Spectrum arriving tomorrow, as I've read that's a good place to start if you don't know what is bothering your fish.

Any help or insight would be appreciated. Thank you in advance from my little koi family.

[richtoybox]

I think that you may have two issues, one is parasites and the other is bacterial. You have the Microbelift Broad Spectrum on order, which is food for most of the parasites, but what you describe with the food spitting sounds like flukes, so I would order some Fluke M, and do the three treatments with the Broad Spectrum, adding the Fluke M with the third dose of Broad Spectrum. Do the water change before each treatment as specified. That will take care of all of the microscopic parasites. Catch the fish, and apply some iodine on the sores to try to cure the bacterial issues. If that doesn't work, then order Tricide Neo from the internet. I follow the instructions for mixing, but mix in a quart size spray bottle and spray the mix on the fish while it is held away from the pond. Some have good results with using it dry applying it with a qtip. Either is more economical than the manufacturers instructions. Put the unused powder in a sealed bag in the freezer for future use.

[Firsttimekoidad]

Thank you so much. I will try what you suggested and let you know how it goes. I appreciate your time.

[fly4koi]

Do what Richard said.