Caprine arthritis encephalitis virus

Caprine Arthritis Encephalitis Virus (CAEV) is a virus that affects goats, causing a disease known as Caprine Arthritis Encephalitis (CAE). This disease is of significant concern in the agricultural and veterinary fields due to its impact on goat health, welfare, and productivity. CAEV is a member of the Retroviridae family, specifically classified under the genus Lentivirus. It is closely related to other animal lentiviruses, such as the Maedi-Visna virus that infects sheep.

Transmission

CAEV is primarily transmitted through the ingestion of infected colostrum or milk from an infected doe to her offspring. The virus can also spread through close contact with infected bodily fluids, although this is less common. Practices such as the communal rearing of kids and the use of shared milking equipment can facilitate the spread of CAEV within a herd.

Clinical Signs

The clinical manifestations of CAEV are diverse, with the disease progressing in several stages. Infected goats may develop arthritis, characterized by swelling and pain in the joints, leading to decreased mobility. In young goats, CAEV can cause encephalitis, presenting as neurological symptoms such as incoordination and weakness. Other signs include pneumonia, mastitis (inflammation of the mammary glands), and weight loss. However, many infected goats may remain asymptomatic carriers of the virus, making the control and eradication of CAEV challenging.

Diagnosis

Diagnosis of CAEV is primarily based on serological tests, such as the enzyme-linked immunosorbent assay (ELISA), which detects antibodies against the virus in the blood. Polymerase chain reaction (PCR) tests can also be used to identify the presence of viral RNA in blood samples. Early diagnosis and segregation of infected animals are crucial steps in controlling the spread of the disease within a herd.

Prevention and Control

There is no cure for CAEV, but the disease can be managed and its spread minimized through various biosecurity measures. These include testing new animals before introducing them to the herd, segregating infected animals, using pasteurized milk or colostrum to feed kids, and implementing strict hygiene practices during milking. Breeding programs aimed at selecting for resistance to CAEV may also contribute to long-term control efforts.

Economic Impact

The economic impact of CAEV on the goat industry is significant, with losses stemming from decreased milk production, reduced fertility, increased veterinary costs, and premature culling of affected animals. The disease also poses a barrier to the international trade of goats and goat products.