2. HORSES: Equine Viral Arteritis (EVA) (ARTERIVIRUS)

Question 1

disease

Answer 1

-contagious disease of equids

-equine viral arteritis (EVA)

Question 2

caused by

Answer 2

arterivirus

Question 3

characterized by

Answer 3

fever, vascular lesions and edema

Question 4

agent

Answer 4

-agent: Equine Arteritis Virus (EAV)

> genus: arterivirus

> family: arteriviridae

> RNA virus

> 1 serotype

Question 5

can remain viable for

Answer 5

• 2-3 days in 37-38 degrees, and <75 days in 4-8 degrees

-semen remains infectious after freezing

Question 6

sensitive to

Answer 6

sunlight and low humidity

Question 7

readily inactivated by

Answer 7

detergens, common disinfectants and lipid solvents

Question 8

HR

Answer 8

-equids

> illness occurs mostly among HORSES and ponies

> reported in horses, ponies, donkeys and zebras

Question 9

reported in (countries)

Answer 9

-North and South America

-Europe

-Asia

-Africa

-Australia

> common among horses in continental Europe (manner Eurooppa)

> absent from Iceland and Japan

Question 10

In Europe (EU) seroprevalence is particularly high among __

Answer 10

-WARMBLOODS

> in U.S - Standardbreds

Question 11

notifiable dz

Answer 11

YES

Question 12

morbidity and mortality

Answer 12

-abortion rate varies: <10% - 60%

-deaths are RARE in healthy adults:
>YOUNG FOALS ARE MORE LIKELY TO DIE

Question 13

distribution 2019 (JAN-JUN)

Answer 13

-USA

-eu

Question 14

distribution 2022

Answer 14

-usa

-eu

Question 15

distribution 2023

Answer 15

-usa

-canada

Question 16

outbreaks 2005-2019

Answer 16

-usa

-uk

-africa?

Question 17

outbreaks 2021-23

Answer 17

not any

Question 18

transmission: excretion- ACUTE stage

Answer 18

-RESPIRAOTRY SECRETIONS; URINE AND FECES

Question 19

transmission: ACUTELY INFECTED MARES; ACUTELY/CHRONICALLY INFECTED STALLIONS

Answer 19

-REPRODUCTIVE TRACT

-SEMEN

Question 20

transmission: ways

Answer 20

-venereal transmission

-aerosol transmission

-direct contact

-fomites

Question 21

transmission: route

Answer 21

-venereal

or

-respiratory

Question 22

10-70% of infected stallions become

Answer 22

-CARRIERS

> virus nt found in respiratory secretions, blood, or urine of carriers
found ONLY in SEMEN !!!!

Question 23

IP

Answer 23

• 2 days to 2 weeks

> venereal transmission: infection occurs generally in 1 week

Question 24

CS: most cases

Answer 24

asymptomatic

Question 25

CS: more severe in

Answer 25

old or very young animals, AND in horses that are immunocompromised or in poor condition

Question 26

CS

Answer 26

-fever, depression, anorexia

-limb edema (hindlimb)

-dependent edema of prepuce, scrotum, mammary gland and / or ventral body wall

Question 27

CS: also may be seen

Answer 27

-conjunctivitis

-photophobia

-periorbital or supraorbital edema and rhinitis

-utricaria

Question 28

CS: mares that were pregnant on exposure

Answer 28

abortions and stillbirths

Question 29

CS: in stallions

Answer 29

-scrotal edema

-temporary decrease in fertility, incl. reduced quality sperm and decreased libido

> can persist up to 4 months

> quality of semen is not decreased in carrier stallions

Question 30

CS: in foals

Answer 30

-fulminant infections with severe interstitial pneumonia (keuhkokuume, keuhkokudoksen välitilassa)

and / or

-enteritis (suoliston limakalvon tulehdus)

Question 31

PM

Answer 31

-edema, congestion and hemorrhages of subcutaneous tissues, visceral organs and LNs

> limbs , abdomen, thoracic and abdominal LNs, small and large intestine (especially colon and cecum)

-clear, yellow fluid in peritoneal cavity, pleura and pericardium

Question 32

PM: foals

Answer 32

-pulmonary edema

-interstitial pneumonia

-emphysema (keuhkorakkuloiden sairaus)

-splenic infarcts (pernan verenkierron äkillinen pysähtyminen)

-enteritis

Question 33

PM: mares that abort

Answer 33

-endometrium (kohdun limakalvo) swollen and congested, can contain hemorrhages

Question 34

PM: aborted fetuses

Answer 34

-partially autolyzed

-excess fluid in body cavities and signs of interlobular interstitial pneumonia

Question 35

DDx

Answer 35

-equine influenza

-equine infectious anemia

-african horse sickness

-getah virus

-hendra virus

-equine rhinitis A and B viruses

-equine adenoviruses

-equine herpesvirus 1 and 2

-purpura hemorragia and other streptococcal infections

Question 36

diagnosis: suspect when

Answer 36

-fever

-depression

-edema

-conjunctivitis

-nasal discharges

-abortions

Question 37

diagnosis: material

Answer 37

-nasopharyngeal swabs

-conjunctival swabs

-blood

-semen

-tissue samples: cecum, colon, spleen and associated LNs, adrenal cortex

Question 38

diagnosis: material: in aborted fetuses

Answer 38

-placenta

-fetal fluids

-fetal tissues (esp. lymphoid tissue)

Question 39

diagnosis: material: foals

Answer 39

-lungs

-liver

-spleen

Question 40

diagnosis: in the lab

Answer 40

-virus isolation

-detection of antigens or nucleic acids: RT-PCR

-serology: ELISA, MIA

-histopathology

Question 41

diagnosis: detecting carriers

Answer 41

-virus isolation from semen

or

-breeding with 2 seronegative mares

> detecting carriers: mares are checked for seroconversion 4 weeks after breeding

Question 42

Tx

Answer 42

-no specific Tx

-symptomatic and supportive care

Question 43

control

Answer 43

-infected should be isolated= prevent transmission

-venereal transmission controlled by good management and vaccination

-new horses: isolate 3-4 weeks

-excellent hygiene and decontamination of fomites

Question 44

control: carrier stallions

Answer 44

-bred only to well vaccinated or naturally seropositive mares

> same for semen use

Question 45

vaccination

Answer 45

-YES = prevents long term carriers

-first-time vaccinates can shed for short time
> separated from others
> especially from pregnant mares