Iowa Code § 64.21: Approval by auditor.

When a bond, approvable by the board of supervisors, of any public officer is presented after the final adjournment of the January session of said board, except those of the county auditor and treasurer, the auditor may approve such bond, in which case the auditor shall report that action to the board at its next session. The action of the auditor in approving the bond shall stand as the action of the board unless the board enters its disapproval. If such disapproval be entered, the new bond must be given within five days from the date of such decision, but the old bond shall stand good for all acts done up to the time of the approval of the new bond.