39. Avian encephalomyelitis.

Question 1

Avian Encephalomyelitis: Causing Agent

• Family
• Genus

Answer 1

• Family: Picornaviridae
• Genus: Tremovirus

Question 2

Avian Encephalomyelitis: Alternative Name

Answer 2

Epidemic Tremor

Question 3

Avian Encephalomyelitis: Summary

Answer 3

• Avian encephalomyelitis virus
• High resistance; One serotype

Question 4

Avian Encephalomyelitis: Susceptible species

Answer 4

• Chicken
• Pheasant
• (Turkey)
• (Quail)

Question 5

Avian Encephalomyelitis: Epidemiology

Answer 5

• Shedding via the faeces for several weeks
• Fast spread withing the flock
• 50-60% morbidity; High lethality

Question 6

Avian Encephalomyelitis: Pathogenesis

Answer 6

PO infection → GI mucosa → Viraemia →

• Pancreas
• Liver
• Spleen
• Kidney
• Ovary
• CNS

Good immunity & maternal protection

Question 7

Avian Encephalomyelitis: Incubation & CSx (Adult chicken)

Answer 7

Incubation time: 1-11 days

• CNS signs: Depression; Ataxia; Tremor; Paralysis
• Ø Eating; Ø Drinking; Diarrhoea; Opaque lenses
• Death

Question 8

Avian Encephalomyelitis: CSx (Older animal)

Answer 8

• Subclinical
• Egg production drop

Question 9

Avian Encephalomyelitis: Pathology

Answer 9

• Ø Macroscopic signs
• Histopathology:
  
  • CNS; Grey matter; Cerebellum; Brain stem; Spinal cord
  • → Lymphocytic infiltration; Neural degeneration; Glica replication

Question 10

Avian Encephalomyelitis: Dx

Answer 10

• CSx; Epidemiology; Histology
• Direct: PCR; IF; Isolation
• Indirect: VN; ELISA

Question 11

Avian Encephalomyelitis: DDx

Answer 11

• NDV (Newcastle disease)
• Avian influenza
• Marek’s disease
• Encephalomalacia

Question 12

Avian Encephalomyelitis: Tx

Answer 12

Ø Treatment available

Question 13

Avian Encephalomyelitis: Prevention

Answer 13

• Epidemiological methods
• In case of fresh infection → Ø Hatching for 1 month
• Vaccine:
  
  • Live vaccine; Given in drinking water
  • Layers: Vaccinated 1 month before laying