| I have no idea as to the cause. I'll ramble on with some thoughts in hope something gives you an idea.
First, the symptoms sure look like a bacterial infection with fraying of fin edge and internal corruption. This is usually related to water conditions and stress on the fish, but can also have a parasitic injury involved. Essentials are clean water without organic pollutants. (Absolutely no ammonia or nitrite and preferably nitrate down to 10ppm or less.) If water temps have been excessively high, they need to be brought down to around 75F so immune system functioning at high level. Try shading the pond. (If water was cold, it would be time to try to raise the temperature to 68+F.) If the fish is eating, medicated feed should help, but never can know whether getting a proper dose. If the fish is not eating, and you are not prepared to inject antibiotic, I'd recommend using an inexpensive antibiotic, erythromycin, dissolved in the water containing the fish. Will likely need a 'hospital tank', since repeat dosing daily for 7-10 days is required. (Erythromycin is readily available for aquarium use. Find a bulk source. The price per tab at retail pet shops is ludicrous.)
But, while treating the infection, need to get to the bottom of why there is a problem. Healthy fish in good water fight off these things all the time. Why isn't yours able to ward off the infection? If you had anchor worm infestation, I think you would have noticed. ...very distinctive. I've seen similar secondary effects from flukes in high water temperatures... I think due to immune system being depressed by heat and parasitic injuries resulting in all sorts of skin and infection problems. I've also seen it when fish coming out of cool/cold water undergoes shipping stress and goes into less than ideal warm water.
I'm thinking there could be stress from high metal content of water inhibiting immune system, lots of changing conditions with the pH issues/ acid additions, etc.
Those are some thoughts for whatever they are worth.
Good luck getting to the bottom of it. |