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Dr. B.
Dr. B., Board Certified Veterinarian
Category: Vet
Satisfied Customers: 22463
Experience:  General practice veterinary surgeon with extensive experience in a wide range of species.
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I noticed over the last few days that one of my small carp

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I noticed over the last few days that one of my small carp was sitting at the bottom of the pond a lot but appeared to be eating algae still & swimming as normal if disturbed. A little concerned I took him/her out to examine 2 days ago & the rib cage seemed to be pretrubing & a little red & sore so as a precaution I treated with medi fin. Today he is sitting on the bottom of the pond & his spine looks really thin, I don't want to disturb him again but not sure if should separate him or if there is anything else I can do? All the other fish look happy & healthy & have been spawning & it is a well established pond. Please can you help?

Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.


Could you actually see rib bones protruding from the wound?

Or did it look like an ulceration of skin where the scales had been?



Customer: replied 3 years ago.

It looked like bones protruding through the skin.

Hi Sue,

First, I must say that I am quite concerned abotu this wee fish. And while I do want you to limit any stressors to him, I would just note that if you happened to take photos when you had him out last (some people do), then I would be very keen to have a look at what you are seeing. If you had and wished to post photos for me to see your fish, you can do so by using the wee paper clip on the tool bar (How To). Or you can post them on a 3rd party site (ie Flickr, Photobucket, etc) and paste the web address here.

Anyway, the reason I asked about the bone exposure you had noted initially is because bone penetration is quite a serious situation for any fish. Now we can see general lesions of this nature (without bone) due to trauma (either due to predators but also erosions from bottom sitting for other reasons) or bacterial (usually Aeromonas) infection.

Now if we actually have protruding bone, then this would suggest traumatic damage to this fish. And in that case, I must be honest and say that if there has been chest penetration then this koi has a very poor to grave prognosis (since you will be hard pressed to replace the bones, amend any fractures, amputate any protrusions, and avoid potential bacterial infection gaining access to the chest cavity.) And even if he appears to be eating, the wasting along our spine that he is not doing so adequately (perhaps because of pain but also he will no longer be competitive with the other fish).

In regards XXXXX XXXXX to approach this poor wee one, I would strongly advise isolation into a hospitalization tank at this stage. It will allow you to better monitor/treat him, reduce competition for him, and allow you to keep an eye on whether he is eating or not. You can continue the Medifin to limit the infection to the tissue, though ideally you may want to see if a local vet can order in water soluble antibiotics for this wee one (ie kanamycin, erythromycin or tetracycline, used in combination with minocycline) to give you the best chance of staving off infection.

Finally, I do want to note since this fish has a truly poor prognosis if there is communication into the chest cavity (via the bones sticking out), that if you do not see positive response to treatment over the next few days, then you may need to consider euthanasia for this fish. If we have to do so, then most humane way is via the use of Clove Oil and I do want to leave you information on doing so if necessary (More Info).

Please take care,

Dr. B.


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