Koi can still be fed during the tooth - changing period. Koi's teeth are not sharp. They are mainly used for grinding food to aid digestion. So, feeding during the tooth - changing period won't have a significant impact on their teeth.
During the tooth - changing period, it is recommended to feed some easily - digestible and easy - to - swallow foods, such as tubifex worms. Tubifex worms are rich in protein, fat, and vitamins. They are small in size and soft, making them easy for koi to swallow. Before feeding, the tubifex worms need to be rinsed repeatedly. If possible, let the tubifex worms expel all the mud before feeding. Besides, other easily - digestible foods like fish feed can also be chosen.