diseases causing abortion
DESCRIPTION
Pathology of Brucellosis, Campylobacter, trichomnas, and viral diseasesTRANSCRIPT
Placenta
The placenta, as a diverse organ, is involved with the exchange of nutrients and
other substances between the fetal and maternal tissue interface. In addition to its
function in protecting the developing fetus, the placenta produces enzymes,
prostaglandins and cytokines necessary for the attachment and stability of the fetus, and
transient hormones such as estrogen and progesterones to maintain pregnancy. Placentas
are classified according to their gross and microscopic anatomy and on the basis of the
degree of proximity of the fetal circulation to that of the mother (see following table).
The fetus is surrounded by two sets of fetal membranes, which are separated by cavities
containing defined amounts of fluid. The outer fetal membrane is the allantochorion,
which is formed by fusion of the chorion and allantois. The chorion opposes the
endometrium, while the allantois borders the allantoic space with its allantoic fluid. The
allantoic fluid is composed of hypertonic urine and fetal excretory products. The second
fetal membrane is the allantoamnion formed by the fusion of amnion and allantois. The
allantoamnion envelops the fetus. The allantoamniotic space contains mucinous, amniotic
fluid, which is composed of fetal urine and secretions from the fetal respiratory tract and
oral cavity. The only attachment of the fetus to the fetal membrane is through the
umbilicus. Both an amniotic and allantoic membrane covers the umbilical cord as it
passes through the two spaces. It contains two umbilical arteries, one or two umbilical
veins and the urachus.
Placental classification
Species Distribution of Contact Microscopic Classification
Mare, Sow Diffuse Epitheliochorial
Bitch, Queen Zonary Endotheliochorial
Ruminant Cotyledonary Epitheliochorial
Primates Discoid Hemochorial
Placental Membranes Both fetal membranes are spread out, the chorioallantois with its flaky, velvety, reddened
chorionic surface visible and the amnion as a thin, translucent membrane containing
coiled muscular arteries.
Amnion The allantoamnion is a thin, white, translucent membrane that completely envelopes the
fetus and contains accentuated, coiled, muscular arteries
Incidental Findings on Fetal Membranes
Calcium
Calcium is deposited in a rather loose network in the chorion of sheep, cattle and swine.
This is a physiologic process and in cattle the calcium is present when the fetal size varies
between 2.5 and 25 cm. Therefore, calcium is not present in visible quantities before 60
days but is usually present from this time until about 4 months of gestation. Distribution
of calcium suggests that it is deposited along the course of capillaries. The calcium
deposition is a physiologic process. It creates a depot of calcium in the chorion for the
rapidly growing fetus. The fetus draws upon this deposit at the time of increasing calcium
needs.
Epithelial Plaques
These are present in the amnion of cattle. They consist of focal areas of squamous
epithelium, which often becomes keratinized. Occasionally the epithelial plaques will
become infolded and will form spherical cystic structures filled with keratinized
epithelium. These sometimes become detached from the amnion during parturition.
Hippomanes (Hippo =ipecac=dried roots). They constitute amorphous, rubbery masses of material, which develop from the
deposition of material from allantoic fluid on a central nucleus of desquamated cell
debris. They are actually allantoic calculi and are usually free floating in the cavity.
Amorphous globosus Round, hard cystic structures next to the umbilical cord. They are considered incomplete
twins or "teratomas".
Accessory cotyledons or adventitious placentation: it is a common lesion in older cattle.
In fact, it is rare to find a placenta that does not have some degree of development of
adventitious placenta. However, in advanced cases when there is a very diffuse
placentation, there may be pathologic significance. In some of these cases, there appears
to be a tendency for this to be associated with hydrallantois. Adventitious placentation
appears to be more pronounced in cows, which have had postpartum metritis.
Retained Placenta: This condition occurs less commonly in the horse than in the cow.
Retained placentation is associated with abnormalities of parturition such as dystocia,
twin delivery abortion and cesarean section. Placental edema has been suggested for
failure of microcotyledons to detach. In cattle, retention occurs in situations of
hyposelenosis.
Torsion A rotation of the pregnant uterus along its longitudinal axis leads to vascular
compromise, devitalization of the uterine wall and fetal death.
Embryonic and Fetal Death
The pathology of the early conceptus is complex and focuses on chromosomal
abnormalities of the zygote, transport problems through the uterine tubes and attachment
or implantation problems within the endometrium due to diseases of the blastocyst or
preexisting diseases of the endometrium. Early embryonic death resorption, or expulsion,
may be the outcome of such conditions. The early conceptus disintegrates and a normal
estrus cycle may occur. Viruses, several bacteria, mycoplasma species, fungi (Candida
spp.) and drugs may cause damage to the zygote and early embryo.
Mummification Fetal death has occurred in a more differentiated stage of gestation. If no bacteria are
present, the fetus is maintained in the uterus where it undergoes slow decomposition and
dehydration (mummification). The cervix usually remains closed. The fetus appears as a
brown, dry, leathery structure. In a cow and sow, fetal mummification has been
associated with some viral infections, but the condition is not necessarily indicative of
any specific etiology.
Diseases Causing Abortion
Abortion: It is defined as the expulsion of a dead fetus or living conceptus at any period of
gestation. Dead fetuses expelled at term are called stillbirths. Viable fetuses born before
expected parturition are called premature birth.
Causes:
I-Non-Infectious Diseases: Non-infections causes of abortions are most difficult to
determine and vary between animal species. It may include:
1-Toxic a-Plant eg. (Nitrate, ergot, Lupinus).
b-Anthelmintics eg. (Benzimidazoles).
c-Mycotoxins eg. Aflatoxins,..
2-Hereditary eg. Protoporphyria.
3-Metabolic eg. Iodine or Vit. A deficiency and both selenium deficiency and selenium
excess
4-Dystocia (any abnormalities during birth), which leads to Intra or Post-Partum death.
5-In horses, twinning, premature placental separation, placentation insufficiency,
umbilical abnormalities.
II- Infectious Diseases: For the infectious process to affect the fetus, penetration of the agents through the
placental membranes is necessary. The placental types encountered in specific animal
species, as well as different responses of the fetus to the individual agent, need to be
evaluated as well. The type of reaction to infectious agent insults is different in the fetus
as compared to perinatal, postnatal and juvenile animals. Abortion ensues secondary to
fetal death whether it is due to damage to the pregnant uterus, placental membranes or
fetus. Hematogenous versus transcervical routes are major modalities of infection. There
are three principal infectious manifestations in which abortions can be expected:
a. Maternal systemic infection of the dam as with leptospirosis, salmonella septicemia or
equine viral arteritis.
b. Placental infections, as with brucellosis.
c. Fetal infection as with herpesvirus.
i-Bacterial - Induced Abortions In principle, infectious causes of abortion are more
common than non-infectious. Infectious agents may contribute to up to 80% of bovine
abortions, up to 60% in the horse and up to 80% small ruminants. A variety of gram-
positive and gram-negative bacterial species are recognized as abortifacient. Brucella,
Campylobacter, Leptospira, Listeria, Salmonella, Chlamydia and others.
ii-Viral Abortions Viruses may reach the fetus by one of three basic mechanisms:
a-Direct infection by way of the vagina and cervix.
b-Transplacental transmission from the mother to the fetus.
c-Infection of the ovum (transovarian transmission).
Examples of some specific viral abortion diseases: IBR, BVD, Blue tongue, RVF and
Equine Viral Arteritis.
iii-Protozoal Abortions: for examples: Trichomonas, Neospora, Toxoplasma,
Sarcocystis.
iv-Mycotic Abortions: Mycotic abortions are mainly encountered in cattle as sporadic
events and are commonly caused by Aspergillus spp., Absidia spp., Mucor spp., Rhizopus
spp. and Mortierrella wolffii. Abortions occur late in pregnancy and the placenta is often
retained. When passed, it has a thickened, dry appearance.
v-Mycoplasma, Ureaplasma and Rickettsia: For examples: Mycoplasma
bovigenitalium, Coxiella burnetii (Q fever).
vi- Unclassified Abortifactive Agent (Foothill Abortion): A tick-borne abortion
disease of cattle.
Brucellosis
Bangle’s Disease (Animals)
Undulating Fever (human)
Causes: B. abortus (cattle)
B. melitensis and B. ovis (sheep)
B. suis (swine)
Pathogenesis:
The infections are through the digestive tract, conjunctiva, vagina and skin or from
infected bull and AI. The organism reaches the digestive mucosa then to mesenteric
Lns. engulfed by macrophages, where it multiplicates migrate through LV. to
thoracic duct then to the blood (bacteremia) without any clinical signs.
In pregnant uteri, the organism attracted the uterus by the effect of Erythrinol
substance (secreted from gravid uterus) then invaded the fetal membranes
(placenta), uterine mucosa mammary gland and Lns of uterus and udder.
In non-pregnant uteri (calf or heifer), the infection via milk of infected dam reached to
udder and its Lns. (supramammary) and stay till pregnancy.
In Bull, after bacteremia the organism localized in testes, epididymis and seminal
vesicles.
Campylobacteriosis
(Vibriosis)
Genital Form Abortion and infertility
Causes: Campylobacter fetus Intestinal Form Enteritis and diarrhea
Pathogenesis:
In cow, through coitus (Venereal disease).
In ewe, through ingestion of contaminated food.
The organism reaches the capillaries between the maternal and fetal sides obstruction
hypoxia and death of fetus expulsion outside (abortion).
NB: The infection in cow lead to acquired resistance to reinfection (but in brucella,
repeated abortions).
Bovine Genital Trichomoniasis
Causes: Tritrichomonas fetus
Pathogenesis:
The protozoan live in preputeal cavity (venereal) balanitis, seminal vesiculitis and
epididymitis infected semen reach to vagina (Vaginitis) and uterus
(endometritis).
Salmonellosis
Causes: Salmonella abortus equi (in equine) transmitted by coitus (venereal).
Salmonella abortus ovis (in sheep) transmitted by ingestion.
Pathognomonic Lesions of These Diseases: Summarized in the following tables.
Pa
tho
gn
om
on
ic L
esio
ns
Co
w/B
ull
Nec
roti
c o
r
sup
pu
rati
ve
orc
hit
is,
epid
idy
mit
is,
ves
icu
liti
s,
py
oce
le
Dif
fuse
mu
cop
uru
len
t
end
om
etri
tis,
vu
lvo
va
gin
itis
Sep
tice
mic
lesi
on
s
Sep
tice
mia
an
d
ence
ph
ali
tis
circ
lin
g d
isea
se
En
do
met
riti
s
an
d P
yo
met
ra
No
ne
Pu
stu
lar
vu
lvo
va
gin
itis
ba
lan
op
ost
hit
is
Nec
rosi
s in
GIT
an
d L
ym
ph
oid
tiss
ues
.
Fet
us
1-S
ero
sin
gu
inou
s fl
uid
in
s/c
&
intr
am
usc
ula
r.
2-B
ron
cho
pn
eum
on
ia a
nd
ple
uri
tis.
3-F
ibri
nou
s ex
ud
ate
in
B. ca
vit
y.
4-S
ple
en a
nd
L.n
. en
larg
ed &
nec
roti
c.
5-O
mp
ha
lop
hel
ebit
is,
emb
oli
c n
eph
riti
s
1-R
edd
ish
-bro
wn
flu
id i
n a
ll B
. ti
ssu
es
an
d s
tom
ach
.
2-F
lak
es o
f p
us
on
per
ito
neu
m.
3-F
oca
l n
ecro
tic
hep
ati
tis.
1-F
eta
l d
eath
2-A
uto
lyti
c fe
tus.
3-I
cter
us
ma
y o
ccu
r
Nec
rosi
s a
nd
mic
roa
bsc
ess
in t
he
liv
er.
1-F
ibri
nou
s p
oly
sero
siti
s.
2-B
ron
cho
pn
eum
on
ia
An
asa
rca
, ly
mp
ha
den
op
ath
y,
tra
chea
l
pet
ech
ea
1-F
oca
l n
ecro
sis
in l
iver
, L
n,
sple
en a
nd
kid
ney
s. (
IN/I
B i
n r
esp
ira
tory
ep
ith
elia
.
Co
ng
enit
al
ma
lfo
rma
tio
ns
eye
an
d b
rain
.
Pla
cen
ta
1-F
oca
l n
ecro
tic
pla
cen
titi
s.
2-P
lace
nta
is
thic
k,
e
dem
ato
us,
du
ll (
op
aq
ue)
an
d l
eath
ery.
3-N
ecro
sis
of
Coty
led
on
s.
4-R
etain
ed p
lace
nta
.
1-S
emi-
op
aq
ue,
lit
tle
thic
ken
ing a
nd
ed
ema. 2
-
Pet
ech
iae
(dark
-red
are
as
wit
h r
ad
iate
d d
ark
str
eak
s
3-N
ot
reta
ined
.
1-A
vasc
ula
r p
lace
nta
2-y
ello
wb
row
n c
oty
led
on
s
3-P
lace
nta
is
slig
htl
y
infl
am
ed a
nd
ed
emato
us.
-Nec
roti
c p
lace
nti
tis.
-No r
eten
tion
Pla
cen
titi
s w
ith
red
-bro
wn
exu
date
& m
icro
ab
sces
ses
of
coty
led
on
s
1-C
oty
led
on
s are
dark
red
.
2-P
erip
lace
nto
me
is
thic
ken
ed,
op
aq
ue,
yel
low
ish
pin
k a
nd
cover
ed w
ith
cla
y
colo
red
exu
date
.
Pla
cen
titi
s an
d n
ecro
tic
coty
led
on
s.
No m
acr
o l
esio
ns
Ab
ort
ion
Tim
e
6 -
9
mon
ths
(late
)
3 -
5
mon
ths
Late
,
6
mon
ths
6 -
8
mon
ths
Last
tr
imest
er
Late
,
6 -
9
mon
ths
> 2
mon
ths
4 -
9
mon
ths
Rate
Hig
h
Low
5-2
0%
Low
0-3
0%
Low
Up
to
15%
Low
Les
s
5%
Sp
ora
dic
Hig
h
Sp
ora
dic
Ro
ute
of
infe
ctio
n
Dig
esti
ve
tra
ct,
Co
nju
nct
iva,
skin
,
Va
gin
a a
nd
AI.
Ven
erea
l (b
y
Co
itu
s)
Ing
esti
on
or
thro
ug
h s
kin
ab
rasi
on
s
Aft
er s
epti
cem
ia
Fro
m i
nfe
cted
ute
rus
Ing
esti
on
an
d
sep
tice
mia
Ven
erea
l (b
y
Co
itu
s)
Ing
esti
on
Dis
ease
s
Bru
cell
osi
s
B. abort
us
Con
tagio
us
ab
ort
ion
Cam
pylo
bact
erio
sis
(Vib
riosi
s)
Cam
pyl
obact
er f
oet
us
Lep
tosp
irosi
s
L.
pom
on
a
Lis
teri
osi
s
L. m
on
ocy
tog
enes
Act
inom
yce
s
pyogen
es
Ch
lam
yd
iosi
s
Ch
lam
ydoph
ila
abort
us
Bovin
e rh
inotr
a-
chei
tis
(IB
R)
Bovin
e vir
al
dia
rrh
ea
(BV
D)
Pa
tho
gn
om
on
ic L
esio
ns
C
ow
/ B
ull
No
ne
No
ne
Gra
nu
lar
vu
lvo
va
gin
itis
,
S.v
esic
uli
tis
an
d
epid
idy
mit
is
Py
om
etra
&
Va
gin
itis
Ba
lan
op
ost
hit
is
No
ne
No
ne
No
ne
Fet
us
Nec
rosi
s in
th
e li
ver
, ed
ema
an
d
hem
orr
ha
ges
in
th
e w
all
of
ga
llb
lad
der
.
Sk
in p
laq
ues
or
dif
fuse
wh
ite
are
as
No
ne
1-E
ma
cia
ted
or
dea
d f
etu
s, w
hic
h
coa
ted
wit
h p
us.
2-
Fet
al
ma
cera
tio
n a
nd
mu
mm
ific
ati
on
1
-En
larg
emen
t o
f su
per
fici
al
L.n
s.
2-s
ero
us
atr
op
hy a
nd
ed
ema
of
B. fa
t
3-H
yd
roth
ora
x, h
yd
rop
eric
ard
ium
an
d
asc
ites
. (t
ach
yzo
ites
& c
yst
s).
1-w
hit
e fo
ci i
n m
usc
le a
nd
hea
rt
2-F
oca
l h
epa
tic
nec
rosi
s.
3-T
ach
yzo
ites
in
dif
fere
nt
feta
l ti
ssu
e
As
Neo
spo
rosi
s p
art
icu
larl
y i
n b
rain
Pla
cen
ta
Non
e
1-N
ecro
tic
coty
led
on
s (y
ello
w
& s
oft
).
2-
thic
ken
ed, d
ry a
pp
eara
nce
No g
ross
les
ion
s.
1-D
estr
uct
ion
of
pla
cen
ta
wit
hou
t in
flam
mati
on
.
2-L
ittl
e ed
ema.
Th
e p
lace
nta
is
thic
ken
ed,
edem
ato
us
an
d t
he
caru
ncl
es
are
atr
op
hie
d.
No g
ross
les
ion
s, b
ut
mic
ro.
the
pla
cen
ta s
how
foca
l
nec
rosi
s, t
ach
yzo
ites
an
d c
yst
.
1-N
ecro
sis
an
d c
alc
ific
ati
on
.
2-T
ach
yzo
ites
in
tro
ph
ob
last
s
Ab
ort
ion
Tim
e
Usu
all
y
late
4 -
7
mon
ths
Vari
ab
le
Earl
y,
2 -
4
mon
ths
Vari
ab
le
4 -
6
mon
ths
3 –
5
mon
ths
Rate
Sto
rm
Rare
Rare
Mod
e-
rate
5-3
0%
Sp
ora
dic
Sp
ora
dic
Sp
ora
dic
Ro
ute
of
infe
ctio
n
By
in
sect
s
Inh
ala
tio
n
Ven
erea
l
Ven
erea
l (b
y
Co
itu
s) a
nd
AI.
Ing
esti
on
of
spo
rula
ted
oo
cyst
s
Ing
esti
on
Ing
esti
on
of
feli
ne
fece
s
Dis
ease
s
Rif
t vall
ey f
ever
Asp
ergil
losi
s
(
Myco
ses)
Mycp
lasm
osi
s
Myc
opla
sma
bovi
gen
itali
um
an
d
Ure
ap
lasm
a
Tri
chom
on
iosi
s
Tri
tric
hom
on
as
fetu
s
Sarc
osp
ori
osi
s
Sarc
ocy
stosi
s
Sarc
ocy
stis
spp
.
Neo
sporo
sis
Neo
spora
can
inu
m
Toxop
lasm
osi
s
T. g
on
dii
Path
og
no
mon
ic L
esio
ns
Ew
e/R
am
Sev
ere
sep
tice
mia
an
d
Met
riti
s
Met
riti
s in
ew
es
aft
er a
bo
rtio
n.
Orc
hit
is a
nd
Ep
idid
ym
itis
En
do
met
riti
s
Met
riti
s a
nd
Sep
tice
mia
in
som
e ew
es
circ
lin
g d
isea
se
-Su
pp
ura
tiv
e
end
om
etri
tis
(No
cer
vic
itis
)
-Sep
tice
mia
&
Ga
stro
ente
riti
s
No
ne
No
ne
No
t g
enit
al
No
t g
enit
al
Fet
us
1-C
hla
my
dia
org
. in
fet
al
coty
led
on
s.
Ly
mp
hoid
hyp
erp
lasi
a a
nd
ed
ema
in
B.
cav
ity
.
2-R
eta
ined
Pla
cen
ta.
1-O
rga
nis
ms
in s
tom
ach
.
2-N
ecro
tic
hep
ati
tis.
3-F
ibri
nou
s p
erit
on
itis
Bro
nch
op
neu
mon
ia
Pn
eum
on
ia
Nec
rosi
s a
nd
mic
roa
bsc
ess
in t
he
liv
er.
1-B
irth
die
or
die
aft
er b
irth
.
2-S
epti
cem
ia, p
neu
mon
ia a
nd
ga
stro
ente
riti
s.
Ed
ema
of
sub
cuti
s
No
rma
l.
Nec
rosi
s in
th
e li
ver
, ed
ema
an
d
hem
orr
ha
ges
in
th
e w
all
of
ga
llb
lad
der
.
1-N
ecro
tic
men
ing
oen
cep
ha
liti
s.
2-L
un
gs
is e
dem
ato
us
an
d p
neu
mo
nic
.
Pla
cen
ta
1-C
oty
led
on
s are
dark
red
.
2-P
erip
lace
nto
me
is
thic
ken
ed,
op
aq
ue,
yel
low
ish
pin
k a
nd
cover
ed w
ith
cla
y
colo
red
exu
date
.
Nec
roti
c p
lace
nti
tis
Fib
rin
ou
s p
lace
nti
tis
As
in c
att
le (
Nec
roti
c
Pla
cen
titi
s)
-Nec
roti
c p
lace
nti
tis.
-No
ret
enti
on
1-P
lace
nta
is
thic
ken
ed,
edem
ato
us
an
d n
ecro
tic.
2-H
emato
ma o
r h
emato
cyst
bet
wee
n a
llan
toin
s an
d
chori
on
. (R
etain
ed p
lace
nta
).
Mu
ltip
le s
mall
nec
roti
c fo
ci
in f
etal
coty
led
on
s
Pla
cen
ta i
s th
ick
ened
an
d t
he
coty
led
on
s is
nec
roti
c
Non
e
Pla
cen
ta i
s on
ly c
on
ges
ted
.
Ab
ort
ion
Tim
e
Last
2 –
3
wee
ks
2
mon
ths
on
-
ward
s
La
te o
r
stil
l-
bo
rn
.
Ab
orti
on
Late
3
mon
ths
Last
6 w
eek
s
Late
or
stil
lbir
th
An
y
tim
e
Usu
all
y
late
1 –
2
mon
ths
Rate
Hig
h
Low
5-2
0%
Rare
Hig
h
Hig
h
Low
Sp
ora
dic
Sto
rm
Sto
rm
Rare
Ro
ute
of
infe
ctio
n
Ing
esti
on.
Ing
esti
on
Co
itu
s fr
om
infe
cted
ra
ms
Ing
esti
on
Ing
esti
on
&
wo
un
ds
Ing
esti
on
Ing
esti
on
of
feli
ne
fece
s
By
tic
ks
By
in
sect
s
By
blo
od
su
ckin
g
art
hro
po
ds
Dis
ease
s
En
zooti
c ab
ort
ion
(Ch
lam
ydia
psi
tta
ci)
Cam
pylo
bact
erio
sis
Cam
pyl
obact
er f
etu
s
Ovin
e B
ruce
llo
sis
(B.
ovi
s)
Ovin
e B
ruce
llo
sis
Bru
cell
a m
elit
ensi
s
an
d B
. abort
us
Lis
teri
osi
s
L. m
on
ocy
tog
enes
Salm
on
ello
sis
(S.a
bort
us
ovi
s a
nd
S.D
ubli
n)
Toxop
lasm
osi
s
T.
gon
dii
Coxie
lla b
urn
etii
Q f
ever
: R
ick
etts
ia
Rif
t vall
ey f
ever
Blu
eton
gu
e /
Its
liv
e
Vacc
inati
on
Pa
tho
gn
om
on
ic L
esio
ns
M
are
/Sta
llio
n
Su
pp
ura
tiv
e
Cer
vic
itis
,
end
om
etri
tis,
sep
tice
mia
an
d
orc
hit
is
Su
pp
ura
tiv
e
art
hri
tis
an
d
fist
ulo
us
wit
her
s
Nec
roti
zin
g
my
om
etri
tis
No
ne
Fet
us
1-B
irth
die
or
die
aft
er b
irth
.
2-S
epti
cem
ia,
Pn
eum
on
ia a
nd
Ga
stro
ente
riti
s
No
ne
No
n-S
pec
ific
1-P
ulm
on
ary
ed
ema
(in
terl
ob
ula
r).
2-N
ecro
tic
foci
in
th
e li
ver
(IN
/IB
).
3-I
ctru
s a
nd
asc
ites
.
4-I
ntr
au
teri
ne
dea
th.
Pla
cen
ta
1-D
ark
or
hem
orr
hagic
.
2-T
hic
ken
ed a
nd
ed
emato
us.
3-H
as
nec
roti
c fo
ci.
As
catt
le
Ed
ema a
nd
nec
rosi
s d
ue
to
vasc
uli
tis.
Non
e
Ab
ort
ion
Tim
e
8 -
11
mon
ths
7
mon
ths
Vari
ab
le
9 –
10
mon
ths
Rate
Hig
h
Rare
Rare
Hig
h
Ro
ute
of
infe
ctio
n
Ven
erea
l
Ing
esti
on
Aft
er V
irem
ia
Res
pir
ato
ry a
nd
Nu
rog
enic
dis
ease
Dis
ease
s
Salm
on
ello
sis
S. abort
us
equ
i
Bru
cell
osi
s
B.a
bort
us,
B.m
elit
ensi
s
Eq
uin
e V
iral
Art
erit
is
(Pin
k E
ye)
Eq
uin
e H
erp
esv
iru
s
Ab
ort
ion