What’s the cause, please?

[MitchW]

Hi everyone,
Today I noticed that I do f the koi fish I had were swimming irregularly. I caught and looked at it and it has some wound, or parasite.
could you please tell
Me what it is and provide some recommendations?
I am in Toronto area. Thank you.

 

[GBBUDD]

looks like an ulser but without scraping and a microscope it could be a parasite as well

 

[MitchW]

looks like an ulser but without scraping and a microscope it could be a parasite as well

Looking at it closer, it looks like it is a parasite of some sort.
Questions is, is it contagious??
Thanks @GBBUDD

 

[Lisak1]

Looking at it closer, it looks like it is a parasite of some sort.
Questions is, is it contagious??
Thanks @GBBUDD

Without knowing what it is, there's no way of knowing if it's contagious. To me it appears to be an ulcer which can be the result of an injury or poor water quality.

Tell us a bit more about your pond - size, filtration, how long has it been running, how many fish and what kind, etc. Do you test your water?

 

[GBBUDD]

If parasitic it feeds breeds spreads every time

 

[MitchW]

Without knowing what it is, there's no way of knowing if it's contagious. To me it appears to be an ulcer which can be the result of an injury or poor water quality.

Tell us a bit more about your pond - size, filtration, how long has it been running, how many fish and what kind, etc. Do you test your water?

Sorry for the late reply, Lisa. I have been crazy busy with work.
I had a friend who knows all these look at it, he thinks that it was pecked by a bird.
The pond details; I have 11K gallon pond, with a huge wetland filter (thanks to advice from this group), small Koi, water is in perfect condition (my friend tested it).