Keratoconjunctivitis sicca (KCS), or “dry eye”, is a common disease of dogs that, since the introduction of cyclosporine, is usually relatively easily managed. Here, we briefly discuss routine management of KCS but then emphasize those patients where cyclosporine (alone) seems relatively ineffective. How are they best diagnosed? What are the potential causes of such cases? Are all cases of dry eye due to aqueous deficiency only? And what is the latest in therapy?