Iowa Code § 639.13: Additional security.

The defendant may, at any time before judgment, move the court for additional security on the part of the plaintiff, and if, on such motion, the court is satisfied that the surety on the plaintiff’s bond has removed from the state, or is not sufficient, the attachment may be vacated and restitution directed of any property taken under it, unless, in a reasonable time, to be fixed by the court, security is given by the plaintiff.