Please help diagnose mystery skin disease

[BrandonMJ]

Hello,
I have a cory cat that has been healthy since I got him over 2 years ago. However, a couple of months ago I noticed a white 'dot' on his head, about the same size as one of his eyes. This has gradually grown to about 4x the size of his eyes, and it appears the skin is simply deteriorating away (the attached pics were taken today). The little guy has so far shown no signs of distress, and continues to eat and explore as usual.

I have searched images and threads all over the internet but so far have seen nothing that looks like this. My water is healthy, I do regular water changes & gravel cleaning (usually twice a month, but I've done cleanings twice a week since discovering this issue). I have 18 fish in a 45g tank, and all of the other fish are doing great with no visible signs of disease or distress.

So far I have done no medications (the last thing I want to do is medicate for the wrong disease and end up stressing out or killing other fish), but I would love to know what this is and how to effectively treat it. Has anyone seen this before? Does anyone know what it is? Any help would be most appreciated!

 

[myswtsins]

Well first thing I always do with these threads is scroll to the pictures before reading anything (I feel it gives me a unbiased opinion to start with) and instantly I thought Hole in Head disease. But to my knowledge that was primarily in big fish like oscars and cichlids. I have no experience with this but maybe you can look into hole in head disease and determine if you believe that is possible.

My quick research does talk about another similar case where they blamed the gravel, you have gravel...maybe. Cories do like to dig and maybe he injured himself.

What other fish are in the tank?

Good job not jumping right to meds and increasing your water changes! *claps* That is a perfect response.

 

[BrandonMJ]

Thanks for the quick response! I thought of HITH disease too, but in further research and looking at lots of pictures, I don't think that's it. In 25 years of keeping fish, I've always used the same type of gravel and never once had an injury that I know of because of the gravel. I suppose it is possible, but probably not very likely. My other fish are:

*a 10-year old YoYo Loach
*a 1-year old Pleco
*three other cory cats
*two zebra danios
*four bosemani rainbows
*five dwarf neon rainbows