Iowa does have a law called "Disruption of hunting pleasure", mainly aimed at anti's and niebours who try to keep the deer in your woods from comming around.....if you can prove that the dogs are his and that the constantly come in the woods and such, nail him...its a $250 fine.

Secondly, are the dogs comming on the property you hunt and does he own it??...if not they can be considered feral and can be shot on site if chasing game animals.