91. Caprine arthritis-encephalitis.

Question 1

Caprine arthritis- encephalitis ?

Answer 1

Caprine arthritis-encephalitis

Retroviridae, Orthoretrovirinae, Lentivirus, CAE virus

Occurrence:

• worldwide, Hungary, mainly dairy goats, rare in rural breeds, wide seropositivity, sporadic clinical
• signs (virus is widespread but not clinical signs - mainly asymptomatic)

Etiology:

Lentivirus, relationship with Maedi/visna virus, virulence variants

Question 2

Epidemiology?

Answer 2

Epidemiology:

• infection via milk and discharges, persistent infection, seropositivity increasing with age
• 2 forms:
• Arthritis (older)
• Encephalitis (less frequent ʹ younger)
• Mainly subclinical infection
• No common transmission from goats to sheep only with sucking
• Horizontal infection: if long contact

Question 3

Pathogenesis?

Answer 3

Pathogenesis:

• infection PO (colostrum, infected macrophages)
• gut, LN, blood, BM (cell-bound viremia) organs
• Joints (replication in synovial membranes):
• older animals (arthritis, bursitis)
• CNS: young animals (encephalitis, demyelinisation)
• Antibodies, cellular immunity: no protective effect ʹ not enough to prevent
• Persistent infection and immune reaction (immune response responsible for clinical signs)

Question 4

Clinical signs?

Answer 4

Clinical signs:

• partly due to virus and Immune response
• Encephalitis: 2-4 months old, anorexia, weakness, ataxia, movement disorders, circling, tremor of head,
• convulsions, death
• Arthritis: > 1 years old, carpus, knee, enlarged joints, weight loss, cannot stand up - no eating, death not
• common
• Respiratory signs mainly in adults, mild inflammation of lungs
• Mastitis: chronic, mild inflammation of udders

Question 5

Pathology?

Answer 5

Pathology:

• encephalitis (leucoencephalitis, demyelinisation, coagulation necrosis)
• arthritis (thickened/ulceration of synovial membrane, joint capsule, increment, erosion of cartilage,
• degeneration, inflammation ofsynovial membrane)
• lung (interstitial pneumonia), udder (lymphoid hyperplasia, mastitis)

Question 6

Diagnosis and differentiation ?

Answer 6

Diagnosis:

• epi, clinical signs, PM lesions
• Detection of virus: PCR, IF, virus isolation
• Detection of antibodies: AGP (blood, milk), ELISA
• Differentiation:
• Arthritis: mycoplasmosis, pygenic bacteria

Question 7

Treatment and prevention?

Answer 7

Treatment:

• NO treatment, symptomatic treatment (anti-inflammatory drugs),
• good bedding, antibacterial drugs for complications

Prevention:

• no mixed milk
• Eradication:
• 1) Selection: test and slaughter: elimination of infected seropositive animals, doe with kid
• 2) Generation shift: isolation of kid right after birth, heat-treated colostrum or milk, serological survery
• twice a year