Canine distemper is recognized as a worldwide problem of carnivores. It has been reported in all families of carnivores, including Mustelidae. The various mustelids (e.g. otters, ferrets) are among the species most susceptible to canine distemper virus (CDV) disease and, with some exceptions, the clinical presentation is similar to that seen in domestic dogs. Veterinarians, including those working with non-domestic carnivores, should be familiar with the clinical signs, diagnosis and clinical management of this disease. This paper is the first description of an acute outbreak of CDV in Asian clawless otter or Asian small-clawed otter (Aonyx cinereus) littermates.