EHV

Question 1

Types

Answer 1

1: respiratory, abortion, neurological signs
2: respiratory, keratitis, conjunctivits
3: coital exanthema
4: respiratory (abortion)
5: respiratory

Question 2

Abortion

Answer 2

• last trimester
• infection via inhalation or recrudescence of latent infection
• foetus/foal often highly infectious –> source of virus to other mares

Question 3

CS (6)

Answer 3

• abortion of fresh foetus in last trimester
• normal/mildly oedematous placenta
• foetus: icterus, pulmonary oedema, petetchiation, white regions of necrosis in liver

Question 4

Dx

Answer 4

-entire foetus/ tissue (liver, lung, thymus, adrenal gland) for histopathology and virus detection (culture, PCR, immunohistochemistry)

Question 5

Management (3))

Answer 5

• closed herd (no movement for at least 28 days)
• prevent exposure of pregnant mare to foals, young horses or transient horses
• vaccination (not 100% effective): 5th, 8th and 9th month of gestation (inactive)

Question 6

perinatal EHV1

Answer 6

• late gestation infection without abortion
• dysmature foal fails to thrive
• invariably fatal

Dx:

• CS
• serology
• virus isolation
• necropsy

Tx:

• IVFT
• NSAIDs
• acyclovir

Question 7

EHV1 myeloencephalitis

• infection
• parthenogenesis
• CS (9)

Answer 7

viral recrudescence/inhalation –> viraemia –> endothelial infection –> immune mediated vasculitis

signs more likely in horses with high circulating Ab

CS:

• URT signs
• pyrexia
• inappetence
• lethargy
• symmetric hindlimb ataxia and paresis
• urinary/faecal retention
• recumbancy
• CN V, VII, VIII, XII
• stabalise in 24-48 hours

Question 8

EHV1 myeloencephalitis

• Dx (5)
• Tx (2)
• Prognosis

Answer 8

Dx:

• history and CS
• CSF
• serology
• viral isolation (PCR/culture)
• necropsy

Tx:

• antiinflammatories: corticostroids, NSAIDs
• supportive: slings, antimicrobials, catheterisation, hydration and nutrition

Prognosis:

• recumbant: poor/grave
• less sever: complete recovery