Distemper Outbreak and Its Effect on African Wild Dog Conservation (February 2002) Marco W.G. van de Bildt,*† Thijs Kuiken,*† Aart M. Visee,‡ Sangito Lema,§ Tony R. Fitzjohn,§ Albert D.M.E. Osterhaus*† *Seal Rehabilitation and Research Centre, Pieterburen, the Nether-lands †Institute of Virology, Erasmus University Rotterdam, Rotterdam, the Netherlands ‡The African Wild Dog Foundation, Schiedam, the Netherlands §Wildlife Preservation Trust Fund, Kilimanjaro Region, Tanzania In December 2000, an infectious disease spread through a captive breeding group of African wild dogs (Lycaon pictus) in Tanzania, killing 49 of 52 animals within 2 months. The causative agent was identified as Canine distemper virus (CDV) by means of histologic examination, virus isolation, reverse transcriptase-polymerase chain reaction analysis, and nucleotide sequencing. This report emphasizes the importance of adequate protection against infectious diseases for the successful outcome of captive breeding programs of endangered species.