A novel approach using vinegar to eradicate recalcitrant skin flukes in koi fish: a case report

Parasites such as skin flukes and gill flukes can be a problem for koi carp owners – particularly hobbyists – for a number of reasons. Although they can theoretically be treated with one application of medication, factors such as water quality, drug resistance and degradation of medications can make these parasites more diffcult to eradicate. Acetic acid can be used as a method of killing ectoparasites on fish, though traditionally this is performed by dipping the fish into the acid, not as a prolonged immersion. This case report concerns a hobbyists pond with a long-term skin fluke infestation and the treatment of the infestation by using household vinegar to acidify the water over a prolonged period.