Treated my pleco for what I consider an ulcer...twice.
Also, had a tetra, who didn't make it in the end...but the initial problem (ulcer) was closed up.
Melafix in both cases...great at healing wounds. But do keep an eye out for other possible symptoms, in case something else is needed. Assuming the wound is on the body...?
>>>water changes?
Clean water always a good thing, esp. when treating.