Although measles (rubeola) and canine distemper must still be considered as distinct clinical entities, there appear to be certain clear-cut relationships between these diseases. Both are characterized by a high degree of contagiousness and have almost identical incubation periods in their respective natural hosts, man and dog. The striking symptoms in both diseases are largely respiratory and consist of fever, cough, coryza, and conjunctivitis. Characteristic rashes are evident, and in the animal they are seen around the mouth and on the chin and abdomen. Demyelinating encephalitis occurs in both measles and distemper in a small proportion of the cases. The most striking similarities may be seen in the pathologic and immunologic findings, which will be the main points to be emphasized in this paper.
Both diseases are caused by viruses, the basic characteristics of which are not fully understood and may prove to be different in many fundamental respects, such