1. HORSES: Equine infectious anemia (EIA) (RETROVIRUS) Flashcards
NÄIVETYSTAUTI
disease
-equine infectious anemia (EIA)
-contagious disease of equids
caused by
retrovirus
characterized by
recurring clinical signs as fever, anemia, edema and cachexia (laihtuminen ja kova lihasmenetys)
agent
-equine infectious anemia virus (EIAV)
-genus Lentivirus, family Retroviridae
destroyable?
readily destroyed by most common disinfectants
survival?
survives limited time on mouthparts of INSECT
host range
-all members of Equine
> clinical cases in HORSES and ponies, also mules
distribution
-found nearly worldwide
> absent in few countries, incl. Iceland, Japan
infections particularly common in? (envi)
humid, swampy regions
presence of EIAV in herd
goes often unnoticed until some horses develop CHRONIC form of dz or routine testing is done
in endemic farms seroprevalence rate
<70%
deaths are
rare in naturally infected horses
distribution 2019
-usa
-russian
outbreaks 2019
-usa
-eu
distribution 2021
russia, usa, eu
distribution 2022
-usa
-russia
-eu
-canada
distribution 2023
-usa
-russia
-eu
outbreaks 2021/22
-usa: peru
-serbia
outbreaks 2023
south eu
virus persist in
-blood LEUCOCYTES
> Can be found in milk and semen
mechanical vectors
biting flies (family: Tabanidae: horse flies, deer flies)
excretions of transmission
-blood transfusion
-contaminated needles, surgical instruments and teeth floats
-In utero transmission
route of transmission
mechanically on mouthparts of biting insects
IP
week to 45 days or longer
some horses remain
asymptomatic until they are stressed
clinical signs
-signs are often nonspecific:
>fever, transient inappetence
>more severe cases: weak, depressed and inappetent
> additional signs: jaundice, tachypnea, tachycardia, ventral pitting edema, thrombocytopenia, petechiae on mucus membranes, epistaxis or blood-stained feces
-anemia = more severe in chronic cases
after initial bout
MOST horses become asymptomatic carriers> some may have recurring clinical signs
inapparent(oireeton) infections may become
symptomatic during concurrent illnesses, severe stress or hard work
donkeys and mules are less likely to
develope severe clinical signs
PM
-spleen, liver and abdominal LNs are enlarged
-MM can be pale
-edema on limbs and along ventral abdominal wall
PM in chronic cases
emaciation
PM: Petechia on (pienet, pistemäiset verenvuodot)
internal organs : spleen, kidney
PM: mucosal and visceral
=hemorrhages
> blood vessel thrombosis
DDx
-equine viral arteritis
-purpura hemorrhagica
-african horse sickness
-leptospirosis
-babesiosis
-severe strongyliasis or fascioliasis
diagnosis: suspect when: individual animals
-weight loss
-edema
-intermittent fever
diagnosis: suspect when: in herd
-several horses have fever, anemia, edema, progressive weakness or weight loss
> particularly when new animals have been introduced into herd or member of herd has died
diagnosis: material
blood
diagnosis: in lab
-serology: AGID, ELISA
> ELISA can be detected antibodies earlier than AGID and it is more sensitive, but false positives are more likely to occur
-RT-PCR:
>determing status of foal born to infected mares: maternal antibodies up to age of 6-8 months
-virus isolation: rarely done
(-inoculation of susceptible horse-monitoring more than 45 days )
Tx? Vaccine?
-NO tx
-NO vaccine
infected horses are
-lifelong carriers
> must be permanently isolated from other susceptible animals or euthanized
foals born to infected mares
-should be isolated from other equids until foal is determined to be free of infection
> risk of congenital infection is higher if mare has clinical signs before she gives birth
during outbreak
-spraying to control insect vectors, insect repellents and insect-proof stabling
-prevent iatrogenic transmission
in countries with no previous infection
-quarantines and movement control
-tracing cases and surveillance
