Canine distemper is caused by the canine distemper virus (CDV), an RNA paramyxovirus that is highly contagious and spreads through direct contact or airborne exposure. CDV attacks the respiratory, gastrointestinal, and nervous systems and it is often fatal with a mortality rate of 50% in adult dogs and 80% in puppies. The virus can also be found in wildlife such as foxes, wolves, coyotes, raccoons, skunks, mink, and ferrets and has been reported in lions, tigers, leopards, and other wild cats as well as seals. Diagnosis is by serology testing for disease-specific IgM or IgG antibodies, RT-PCR analysis, or histopathology.