Yes, it is generally recommended to stop feeding during most medicinal treatments. Professional and effective medications are often irritating and can induce stress in koi. It is advisable to withhold food one day before administering the medication. Feeding should be suspended throughout the treatment period, and normal feeding can resume 48 hours after the final dose, following a partial water change.
This guideline primarily applies to therapeutic agents such as antibiotics, parasiticides, and antifungals. It does not include nutritional or supportive products like vitamin C, multivitamins, probiotics, or other health supplements, which can typically be used without interrupting the feeding schedule. Suspending feed reduces the metabolic and excretory load on the fish, minimizes water quality degradation from uneaten food interacting with medication, and helps the fish focus its energy on combating the illness and managing the chemical stress of the treatment.
