The pathogen which causes caprine arthritis encephalitis (CAE) is a retrovirus and belongs to the genus Lentivirus, just like the maedi visna virus. It is a viral disease in goats which causes encephalitis, arthritis and/or mastitis, depending on the age of the animals affected. Development of clinical signs is slow. Neurological changes and interstitial pneumonia will result in ataxia, lameness, paralysis and respiratory distress. Only about one third of the seropositive animals will contract the disease.
The main transmission route is an infection of newborn animals via the colostrum. A horizontal and intrauterine transmission is possible, but of secondary importance.