Fish Bleeding From The Gills

Bleeding gills is almost always seen in ONLY female fish, after some sort of stress ie. capture and handling, or injection. It is not uncommon in the spring.

It is probable that high levels of the reproductive (estrogenic) hormones make the tissues more 'friable' or soft. These highly vascular tissues can then suffer some bleeding when the fish is stressed. There is no cause for alarm, but obviously the need to handle your koi should be kept to an absolute minimum.

There is no recommended treatment as such, except as previously stated, minimizing handling, and thus, stress. If you do have to handle your fish, provide ample space and plenty of fresh, well aerated water before and after handling.