2. HORSES: Rhinopneumonitis (HERPESVIRUS) EHV-1 and EHV-4

Question 1

disease

Answer 1

-contagious disease of horses

-Rhinopneumonitis

Question 2

caused by

Answer 2

herpesvirus

Question 3

characterized by

Answer 3

respiratory disease and abortions

Question 4

agent

Answer 4

-agent: Equine herpesvirus 1 and 4 (EHV-1 and EHV-4)

> Ubiquitous

> DNA viruses

Question 5

EHV-1

Answer 5

-abortions, sometimes resp.dz

-specific strains of EHV-1-neurologic disease EHM (Equine herpesvirus myeloencephalopathy)

Question 6

EHV-4

Answer 6

respiratory dz, sometimes abortions

Question 7

survival in

Answer 7

environment 15-45 days

Question 8

host range

Answer 8

horses, mules, donkeys

Question 9

where

Answer 9

-worldwide

> Estonia: Harjumaal 2017 rhinopneumonitis

Question 10

listed dz?

Answer 10

yes

Question 11

80-90% go horses are latently infected with

Answer 11

EHV-1 or EHV-4 by 2 years of age

Question 12

protective immunity for only few weeks to few months

Answer 12

EHV-1

Question 13

mostly who

Answer 13

latently infected horses - triggered by stress

Question 14

transmission: excretion

Answer 14

nasopharyngeal excretions, aborted fetal and placental tissues and fluids

Question 15

principal reservoir

Answer 15

latently infected horses

Question 16

shedding virus

Answer 16

6-10 days after onset of fever

Question 17

how transmitted

Answer 17

-direct contact

-aerosols

-fomites

Question 18

route

Answer 18

-respiratory

-alimentary

Question 19

IP

Answer 19

1-10 days

Question 20

respiratory disease CS

Answer 20

-Fever (38.9°–41.7°C)

-Serous nasal discharge

-Malaise (epämukavuus)

-Pharyngitis

-Cough

-Inappetence

-Submandibular or retropharyngeal lymphadenopathy

-SELF-LIMITING dz

Question 21

abortions

Answer 21

-abortion in last 3rd of pregnancy

-no premonitory signs

Question 22

complications

Answer 22

-bacterial pneumonia

or

-pleuropneumonia

Question 23

CS: Equine herpesvirus myeloencephalopathy

Answer 23

-neurologic disease

-vary

-mild incoordination, posterior paresis

-severe posterior paralysis with recumbency

-loss of bladder and tail function

-Loss of skin sensation in the perineal and inguinal areas

-Quadriplegia (4 raajaa halvaantuneet)

-Death

Question 24

PM

Answer 24

-Foals: severe diffuse interstitial pneumonia, hepatitis with viral inclusion bodies and bone marrow depletion

-May have no gross lesions or only minimal evidence of hemorrhage in the meninges, brain, and spinal cord parenchyma

Question 25

DDx

Answer 25

-Respiratory dz:
>Equine influenza
>Equine viral arteritis
>Equine adenovirus

-Abortions
>Equine viral arteritis
>Leptospirosis
>Bacterial placentitis
>Nocardioform abortion
>Neorickettsia risticii
>Chlamydia spp
>Mycoplasma spp
>Mare reproductive loss syndrome

Question 26

material to diagnose

Answer 26

-blood

-nasal swab

-aborted fetuses: liver, Lung, adrenal and thymus samples

Question 27

in the lab

Answer 27

-Virus isolation

-PCR

-Serology – most available tests cannot differentiate between EHV-1 and EHV-4

-Histopathology

Question 28

Tx

Answer 28

-symptomatic Tx

> NSAIDs

> Fluids if needed

> Rest

Question 29

prevention

Answer 29

-Mares that abort should be isolated for minimum of 4 weeks and not mixed with pregnant mares for 56 days

-Good hygiene and biosecurity
>Separate different age groups
>Isolate pregnant mares from other horses
>Disinfection
>Pest and vector control (mechanical vector can transmit secretions)

-Vaccination

Question 30

distribution 2017

Answer 30

-March 2017 in Estonia 3 horses died in Harju county!!

Question 31

cycle

Answer 31

1. infection of foal/adult horse
2. latency established
3. latently infected horse
4. stress
5. virus reactivation

> infection of other foals/adult horses

Question 32

neuropathic strain of EHV-1 produces viremic load 10- to 100-fold higher than

Answer 32

that of non-neuropathic strains