CAE

• Caprine Arthritis Encephalomyelitis Virus (CAEV) is a single-stranded, enveloped, RNA virus belonging to the genus Lentivirus, family Retroviridae.
• The primary mode of transmission of Caprine Arthritis Encephalomyelitis Virus (CAEV) is through the ingestion of virus-infected colostrum or milk by kids.
• Feeding pooled colostrum or milk to kids poses a particular risk, as a few infected goats can spread the virus to a large number of kids.
• Horizontal transmission within herds can occur through direct contact, exposure to contaminated surfaces at feed bunks and waterers, ingestion of contaminated milk in milking parlors, or the use of needles or equipment contaminated with blood.
• The causative agent of Caprine Arthritis Encephalomyelitis is Caprine Arthritis Encephalomyelitis Virus (CAEV).
• CAEV is closely related to ovine lentiviruses that cause ovine progressive pneumonia and maedi-visna in North America and Europe.
• The virus is part of the small ruminant lentiviruses group, and cross-species transmission is possible, especially by feeding infected milk and colostrum.
• The pathophysiology of Caprine Arthritis Encephalomyelitis Virus (CAEV) involves the virus primarily infecting monocytes and macrophages, leading to a persistent, lifelong infection.
• While the Western Blot (WB) is considered the “gold standard” for diagnosis, it is less commonly used for routine screening.
• Commercial herds can implement several strategies to control the spread of CAEV, including permanently isolating kids from their mothers at birth and feeding heat-treated colostrum and pasteurized milk.
• Ultimately, the most effective way to eradicate the virus is through culling of seropositive goats.
• Definitive diagnosis of CAEV often relies on demonstrating characteristic lesions in biopsy or post-mortem specimens due to the limitations of serological testing.
• The quality of the milk is generally unaffected.
• Molecular assays such as polymerase chain reaction (PCR) and isothermal amplification methods are employed to detect CAEV proviral DNA.
• Diagnosis of CAEV requires various laboratory techniques, which fall into two main categories: serological and molecular.
• Currently, there are no vaccines or specific treatments available for caprine arthritis and encephalomyelitis (CAEV), but supportive measures can significantly improve the quality of life for infected goats.
• AGID and ELISA are considered reliable for herd control programs, but they come with limitations.
• While the mammary gland may eventually soften and produce close to a normal volume of milk, many goats with indurative mastitis continue to experience reduced milk production.
• Infected with CAEV, some goats develop the 'hard udder' syndrome, which manifests as a firm, swollen mammary gland and an inability to produce milk upon giving birth (agalactia).
• The virus is transmitted through ingestion of virus-infected colostrum or milk, with periodic replication and maturation of infected macrophages causing characteristic lymphoproliferative lesions in target tissues such as the joints, lungs, central nervous system, and mammary glands.
• CAEV can become sequestered as provirus in host cells, contributing to its persistence.
• The host responds with strong humoral and cell-mediated immune responses, but neither is protective.
• The virus produces antigenic variants, allowing it to evade the immune response.
• The infection can lead to polysynovitis-arthritis in adult goats, encephalomyelitis in young kids, interstitial pneumonia, and a "hard udder" syndrome.
• Caprine Arthritis Encephalomyelitis Virus (CAEV)'s ability to remain latent, induce chronic inflammation, and evade immune responses contributes to its lifelong impact on the host.
• Around 20% of CAEV-infected goats exhibit clinical signs of CAE during their lifetime.
• The most common manifestation of infection is polysynovitis-arthritis, which is seen primarily in adult goats but can occur in kids as young as 6 months old.
• Symptoms of polysynovitis-arthritis include joint swelling and lameness of varying severity.
• The carpal joints are most frequently affected by polysynovitis-arthritis.
• The onset of arthritis may be acute or chronic, but the clinical course is always progressive.
• Affected goats also lose weight and usually have poor hair coats due to Caprine Arthritis Encephalomyelitis Virus (CAEV) infection.
• Encephalomyelitis, an inflammation of the brain and spinal cord, typically manifests in goats between the ages of 2 and 6 months.