Caprine arthritis encephalitis (CAE), diagnosis

Caprine arthritis encephalitis in goats is closely related to the ovine Visna-Maedi virus infection in sheep. Around a third of infected animals get sick; CAE manifests itself in very different symptoms: older goats in particular often suffer from a slowly progressive inflammation of the joints (arthritis), preferably the carpal joints, tendon sheaths, and bursae. As the disease progresses, milk yield decreases, not least due to chronic udder inflammation ("stone udder"). In addition, haggardness occurs due to limited feed intake. The animals mutually relieve their legs by lifting them up and their range of movement becomes smaller, in extreme cases to the point of being stuck. Goat lambs can become infected through virus-containing colostrum or milk (the main route of spread) and develop encephalomyelitis, which itself manifests in weakness or even paralysis of the hindquarters and a hyperextension in the fetlock joint, caused by a virus-induced inflammation of the brain and spinal cord (encephalitis).
The pathogen occurs globally. There is neither a treatment approach nor a vaccination. During herd sanitation, seropositive animals (blood sample) and their offspring must be cauterised. Switzerland has been considered CAE-free since 2018 following a decade-long eradication programme.