Equine Abortion - Infectious Causes Flashcards
1
Q
Pregnancy wastage
A
Embryonic loss
- fertilization - 40 days of gestation
- after pregnancy confirmation
- abortion: 40-300 days
- premature loss/stillbirth: 300-320 days
2
Q
Abortion
A
Termination of pregnancy before fetus is capable of extra-uterine life
- infectious/non-infectious
- in only 60% of cases is a causative agent ID’d
- overall rate is 5-15%
3
Q
Most abortions are the result of placental dysfunction
A
- placentitis
- twinning
4
Q
Clinical signs
A
- premature mammary development (twins)
- vulvar discharge
- absence of any sign is common
5
Q
Signs of placentitis/impending abortion
A
- absence of any sign is common
- premature udder development
- scant vaginal discharge
- uterine thickening observed on US
6
Q
What to do in abortion cases
A
- complete history, recent travel
- submit aborted fetus and placenta
- uterine culture
- isolation of mare until diagnosis
7
Q
Big rule outs for EQ abortion
A
- equine rhinopneumonitis
- ascending placentitis
- nocardioform placentitis
- leptospirosis
- equine viral arteritis (reportable)
8
Q
EHV-1
A
- respiratory disease
- neurological disease
- abortion
9
Q
EHV-4
A
Primarily respiratory
10
Q
EHV transmission
A
- inhalation
- direct contact
- latent carriers
11
Q
Equine rhinopneumonitis
A
EHV-1
- most important cause!
- transmitted via direct contact thru nasal secretions
- latent carriers
- abortion generally occurs after 5 months gestation without maternal signs
12
Q
Equine rhinopnemonitis causes ______
A
Late term abortions
- foal is normal appearing
- fetal lesions: SQ edema, jaundice, enlarged liver with white spots
- no premonitory signs
13
Q
Rhinopneumonitis diagnosis
A
Histopath, liver lesions, VI, FAT, or PCR
- vaccinate preg mares at 5, 7, 9 mos post gestation
- isolate young stock
- maintain closed herd
- avoid contact w/ horses from shows
14
Q
Bacterial placentitis
A
Most common cause of equine abortion!!
- also causes premature delivery and neonatal death
- ascending infection, except w/ lepto and nocardioform
15
Q
Ascending placentitis
A
- udder development
- increased uteroplacental thickness
- vaginal discharge
- compromise of placental function w/ separation of placenta
- fetal death and expulsion ensue
- edematous and thickened chorioallantois
- fibrinous exudate at cervical star region
16
Q
Ascending placentitis occurs in _______
A
Older multiparous mares
- poor perineal conformation
- cervical incompetence
- strep equi sp. zoo (most common)
- e coli
- klebsiella pneumoniae
- pseudomonas aeruginosa
- aspergillus
17
Q
Ultrasonography
A
- combined thickness of uterus and placenta
- cranial to cervix
- distance between middle branch of uterine artery and allantoic fluid
- placental separation
- purulent material
18
Q
CTUP _____ with increasing days of gestation
A
Increases
19
Q
Goals of ascending placentitis treatment
A
Maintain pregnancy long enough to allow fetal maturation (precocious maturation)
- antibiotics
- anti-inflammatory
- tocolytic to prevent uterine contraction
20
Q
Equine mycotic placentitis
A
- ascending
- thickened chorioallantois
- fetus is fresh with growth retardation
- dermatitis
- fungal hyphe seen in placenta, liver, lungs, stomach
- aspergillus, mucor, candida, histoplasma
21
Q
Nocardioform placentitis
A
Actinomycetes
- thickening at base of uterine horns
- late gestation (abortion, stillbirths, weak foals)
- placental lesions (thick, brown exudate)
22
Q
CTUP with nocardioform placentitis will be ______
A
Normal
23
Q
Nocardioform is common in ______
A
Central KY
24
Q
Equine viral arteritis
A
Equine viral arteritis virus
- subclinical infections common
- clinical: fever, conjunctivitis, nasal discharge, abortion, edema (ventrum, limb, eyelid)
25
EVA seropositive status
- standardbred: 85%
- american saddlebred: 25%
- quarter horse: 12%
- thoroughbred: 2%
26
EVA transmission
- aerosol
- venereal
- contact with bodily fluids
- vertical
- fomites
27
EVA pathogenesis
- vascular endothelial cells
| - myometrial necrosis
28
EVA abortion
3-8 weeks after initial infection
- no premonitory signs
- partially autolyzed
29
EVA diagnosis
IHC tissue samples
| - viral isolation via nasopharyngeal swabs, look at buffy coat
30
EVA in carrier stallions
1/3 of stallions
- testosterone dependent (geldings are not carriers)
- virus neutralization assay --> tests for exposure, then do viral isolation
31
EVA vaccination will cause ______
Seropositive status!
32
Management of carrier stallions
- state vet
- isolated from other stallions
- vaccinated mares
- seropositive mares
33
Mare breeding to carrier stallions
- serologic status
- vaccinate and isolate seronegative mares
- seropositive mares isolated 24-48 hrs post breeding
34
Are mares chronic carriers?
No!
35
Prevention of carrier state
- determine serologic status
| - vaccinate 6-12 months of age --> determine and document serologic state before vaccination
36
Leptospirosis
Sporadic cause of equine abortions/placentitis
- generally occurs 6-9 mos gestation
- L. interrogans serovar Pomona type kennewicki is most common in NA
- diffuse lesions due to hematogenous spread
37
Placentitis not involving cervical star
- thick, heavy, edematous, hemorrhagic placenta
- brown edema of the chorion
- funisitis
38
Lepto fetus
Icterus, liver enlargement, nephritis, hepatitis
- dx with MAT on serum of mares and aborted fetuses
- fluorescent antibody test on mare's urien, fetal liver/kidney, placenta
- isolate aborting mares because shedding can last up to 14 weeks
- wildlife are carriers
39
Lepto treatment
- isolate affected mares
- titer exposed to mares
- antibiotics
- prevention: limit exposure standing water, vaccination
40
Dourine
Venereal transmission of Trypanosoma equiperdum (protozoal parasite)
- low morbidity, high mortality
- spread via male to female
- middle east, north and south africa, central and south america
- not present in US
41
Dourine symptoms
Chronic disease
- edema of penis, prepuce and scrotum
- edema of external genitalia, raised plaques and discharge in mares
- test, slaughter and quarantine used for control
42
Piroplasmosis
Babesia caballi, Thelaria equi
- mares have icterus and hemoglobinuria
- excessive fluid in peritoneal/thoracic cavity
- cELISA by USDA lab
- recently in FL, MO, KS, TX
- reportable!!!
