Ch.43DzesoftheReproTract.PT2 Flashcards
What is the most prevalent viral cause of equine pregnancy loss?
equine herpesvirus 1 (EVH-1)
What is the primary route of transmission of EHV-1?
via respiratory tract
Once EHV-1 invades the respiratory epithelium, what is the next step in pathogenesis?
-establishes a leukocyte associated viremia
–>establishesa chronic, possibly life long latent infection
During the initial infection with EHV-1, placental endothelial cells are infected by the virus and transiently present targets to the immune system.
What major part of the immune system is inactivated by EHV-a?
inactivates MHC-1 (major histocompatibility complex-1)– which allows EHV-1 to evade the immune system b/c it stops the ability of cells to present viral particles
In pregnant mares, what is the pathophysiology of reproductive loss/abortion caused by EHV-1?
-after resp infection
-viremia
-infects fetus via transplacental migration of virus bearing leukocytes
-abortion occurs d/t rapid separation of the placenta, causing suffocation of the fetus
What is the time period between infection with EHV-1 and abortion?
Variable: between less than 2 weeks and several months
As with all herpesviruses, EHV-1 establishes a latent infection that makes recrudensce after what?
-after stressful events, such as:
-weaning
-translocation
-introduction of a new animal
-other illnesses
What material is highly contagious from an EHV-1 abortion?
aborted, infected fetal materials are highly contagious
What is the primary lesion of EHV-1?
necrotizing vasculitis and thrombosis resulting from lytic infection of the capillary endothelium
Stage of pregnancy at which abortion occurs with EHV-1
variable: vasculitis is most pronounced from fifth to ninth months of gestation
**95% of abortions occur in the last trimester of pregnancy
What are gross lesions seen on the fetus aborted d/t EHV-1 infection?
-minimal signs of autolysis
-inc fluid in the thoracic and abdominal cavities
-congestion and edema fo the lungs
-hepatomegaly with multifocal, small (~1mm), yellow to white necrotic foci
-subcutaneous edema
-icterus
Histologically, what lesions are seen on the fetus aborted due to EHV-1?
-areas of necrosis in lymphoid tissue, liver, adrenal cortex and the lung
**large intranuclear eosinophilic inclusion bodies0hyperplastic necrotizing bronchiolitis
-Other poss lesions: mild multifocal, necrotizing lesions int eh liver and adrenal cortex
-hyperplastic, necrotizing bronchiolitis
What tissues should be submitted for testing from an aborted fetus, that is to be suspected to aborted d/t EHV-1?
-placenta
-lung
-liver
-spleen
-thymus
When should vaccination to pregnant mares be administered, targeting protection against EHV-1?
5, 7 and 9 months of gestation
If an abortion is caused by EHV-1, what preventative measures should be taken?
-fetal membranes transported away from area w/o contaminating the surrounding environment
-the stall which the mare aborted should be disinfected with a phenolic or iodinophilic compound
-prevent bedding from contaminating other areas on farm
**all pregnant mares on infected farm should remain until foaled
-no horse should leave the farm until 3 to 4 weeks after last abortion
Causative agent of equine viral arteritis?
equine viral arteritis virus (EAV)
What is the primary target of equine viral arteritis virus (EAV)?
vascular endothelial cells and macrophages
Shortly after infection with equine viral arteritis virus (EAV), where can it be found within the horse?
-infects macros and later lymph nodes
-then infects circulating monos
**systemic distribution in 3 days after primary infection–> carrier state
-w/in 1 week EAV infects BV endothelium
abortion caused by equine viral arteritis virus (EAV) is likely due to?
myometritis and vasculitis–> fetal anoxia/placental hypoxia
(secondary to compression of myometrial vessels by edema and decreased progesterone production by the placenta
equine viral arteritis virus (EAV) C/S
+/- absent or highly variable
-pyrexia
-depression
-anorexia
-leukopenia
-limb edema
-stiffness of gait
-rhinorrhea and epiphora
-conjunctivitis
-rhinitis
-urticarial rash
-localized or diffuse edema
-abortion
After infection with equine viral arteritis virus (EAV), when does abortion typically occur?
3 to 10 months of gestation, follows onset of C/S several days up to 2 months
is infection with equine viral arteritis virus (EAV) fatal?
-rarely fatal in adults
-typically fatal to neonates d/t interstitial pneumonia & secondary bacterial infections
What clinical pathological lesions are seen with equine viral arteritis virus (EAV)?
**variable and inconsistent & nonspecific
-hypoxia, hypercapnia
-respiratory or metabolic acidosis
-lymphocytosis or lymphopenia
-neutrophilia or neutropenia
-thrombocytopenia
-hyperfibrinogenemia
What are the most common gross lesions seen with equine viral arteritis virus (EAV)?
edema
congesetion
hemorrhage of the subcu and lymphoid tissues and viscera
equine viral arteritis virus (EAV) histologic lesions are seen where?
vasculature
lymphoid tissues
lungs
intestines
adrenal glands
kidneys
skin
are fetal lesions seen with equine viral arteritis virus (EAV)?
No
What can be long term carriers of equine viral arteritis virus (EAV)?
stallions
**can be transmitted in semen
Diagnosis of equine viral arteritis virus (EAV)
comb of virus isolation, viral nucleic acid (RT-PCR) or antigen detection and serology (virus microneutralization)
equine viral arteritis virus (EAV) transmission
venereally- from PI stallions to mares
Carrier stallions for equine viral arteritis virus (EAV) can be bred, but to which mares?
immune mares
When can mares be vaccinated against equine viral arteritis virus (EAV)?
-safe up to 3 months prior to foaling
**vaccination of pregnant mares in the final 2 months of gestation assoc with inc risk of abortion
What vaccines exist for protection against equine viral arteritis virus (EAV)?
modified live virus
killed virus vaccine
**regulation exists especially for stallions
What serovars of leptospira have been shown to cause abortion in mares?
Leptospira pomona (most common in mares)
-grypotyphosa
-hardjo
-bratislava
-icterohemorrhagiae
What is important in the dissemination of Leptospira from wildlife to horses?
wet environmental conditions–> shed spirochete in urine, which contaminates groundwater and seves as a source for further infections
What are C/s of Leptospirosis in horses?
pyrexia
hemoglobinuria
jaundic
abortion
Is serology helpful in the diagnosis of Leptospira abortions?
No– most horses are seropositive but are subclinical
**serologic antibody conversion lats fr years
What is the best diagnosis for leptospira induced abortions in mares?
flourescent antibody (FA) tests or warthin-Starry (WS) silver stsian of the allantochorion and umbilical cord
How long can horses shed leptospira in urine?
for up to 90 days, affected animals hsoul dbe isoalted and treated wiht antbiotics
Is there a leptospira vaccine available for horses?
Yes- for L. pomona
What is a protozoal cause of abortion?
Neorickettsia risticii (Potomac horse fever)
After infection with Neorickettsia risticii (Potomac horse fever), when is the abortion typically seeen?
2 to 3 months after C/S of ehrlichiosis
What are fetal histo lesions seen with abortions d/t Neorickettsia risticii (Potomac horse fever)?
-enterocolitis
-periportal hepatitis
myocarditis
lymphoid hyperplasia with necrosis of the myenteric lymph nodes and spleen
**recover of protozoan from fetal bone marrow, spleen, LN , colon or liver
In mare reproductive loss syndrome, abortion is associated with ingestion of what?
eastern tent caterpillar (malacosoma americanum)
With mare reproductive loss syndrome and eastern tent caterpillar, where is the toxin located?
related to the larval exoskeleton
**ingestion of
mare reproductive loss syndrome: prior to abortion, what can be seen on ultrasound?
-hyperechoic amniotic and allantoic fluids
-dead or dying fetus (heart rate <75 bpm)
mare reproductive loss syndrome: what characteristic histologic lesions are observed where?
in the placenta and umbilic cord (funisitis)
mare reproductive loss syndrome: pathophysiology of abortion
larval hairs (cetae) are hypothesized to migrate through the gastrointestinal system and translocate commensal organisms from oral cavity and intestines to other sites
mare reproductive loss syndrome: streatment
not possible– usu c/s are absent prior ot fetal death
mare reproductive loss syndrome: preventative measures
-applying insecticides
-physically removing caterpillar nests from trees
-removing black cherry trees
-muzzling mares in pasture
-supplementing hay feeding in pastures to minimize grazing
What spp of salmonella was associated with abortion in mares in the early 1900s?
Salmonella abortus equi
What is the causative agent of Dourine?
Trypansoma equiperdum (protozoan)
What is the pathogenesis of Dourine/ Tryapnosomiasis?
venerally transmitted genital tract infection tha tmay be followed by fatal systemic dissemination in horses (may cause abortion)
Dourine/ Tryapnosomiasis: epidemiology, where is the disease seen?
tropical and subtropical regions
**eradicated from N. america
Dourine/ Tryapnosomiasis control strategies
require ID and tx or euthanasia of infected animls
What is the cause of endotoxemia related abortions?
-release of vasoactive metabolites including PGF2alpha
-shown to cause luteolysis and abortion
Ruminants: in large commericial operations, a low percentage of intermittently occurring abortions is considered acceptable, what is the acceptable percentage?
beef: 2 to 3%
dairy: 10%
When investigating bovine abortions, what commonalities are important to determine?
-stage of pregnancy affected
-sire used
-heifers vs cows affected
-dates of new arrival to herd
-season of year
-vaccination protocols
-presence of dogs
-management practices among different groups
What are noninfectious causes of abortion in ruminants?
-heat stress
-other stress
-nitrate toxicity
-malnutrition (rare)
-pine needle toxicity
-drug induced (corticosteroids)
-physical
Bovine herpesvirus-1 infection manifests as
upper respiratory disease
abortion
In naive cows exposed to BHV-1, what is the pathophysiology in abortion?
-virus carried in leukocytes
-localized in placenta tissues
-fetuses exposed to virus die w/in 24 hours of placental infiltration
What stage of pregnancy is most susceptible to BHV-1 infection?
5 to 6 months
BHV-1 abortion, fetal lesions:
-renal hemorrhagic edema
-acute general necrosis in liver, spleen, kidneys lungs and adrenal glands
-widespread hemorrhage
-petechia
-epithelial destruciton
-hepatic necrosis with intranuclear inclusion bodies
+/- thickened amnion
Diagnosis of BHV-1 caused abortion
-virus isolation from placenta
-ID of intranuclear inclusion bodies in fetal tissues
-immunohistochem
-serum neutrlization testing
Is serum testing useful in diagnosis of BHV-1 caused abortions?
No– as the dam may have been infected moths before the abortion& titer after abortion may be decreasing
BHV-1 abortion prevention
vaccination: vaccinate heifers at 6 months, booster in 3 to 4 weeks before breeding
–> vaccination too close to breeding can lower conception rate d/t normal transient inflamm of repro tract
MLV vaccine (intranasal) available at 3rd to 8th month of gestation– safety questionable
killed vaccine: pregnant cow use
Bovine viral diarrhea virus is what kind of virus?
pestivirus
What can BVDV cause reproductively?
early embryonic death
fetal anomalies
abortion
Pathogenecity of BVDV depends on
-gestational time of infection
-the viral strain
-viral biotype (cytopathic or noncytopathic)
-fetal immunocompentence
What is a common history with BVDV reproductively?
history of repeat breeding and recent episode of febrile dz in herd before onset of abortions
BVDV: when does fetal loss generally occur?
10 to 27 days after exposure, with expulsion of fetus up tto 50 days later
fetus is often autolyzed (may be mummified or fresh
BVDV: what fetal abnormalities are seen?
cerebellar hypoplasia
cerebral malformations (hydraencephaly, porencephaly, microencephaly)
cataracts
brachygnathia
arthrogyroposis
alopecia
thymic hypoplasia
intrauterine growth restriction
Microscopic lesions of BVDV
mild nonsuppurative placentitis
+/- nonsuppurative vasculitis in the placenta, liver or lymph nodes
Viral antigen for detecting BVDV in aborted fetuses can be performed on what tissues?
**seldom virus isolation from fetal tissue is successful
-FA test on kidney, lung, or LN
-fetal thoracic fluid on virus neturalization and enzyme linked immunosrobent assay
Depending on time of exposure to BVDV: what occurs in seronegative cows with exposure at time of breeding?
BVDV prevents conception
Depending on time of exposure to BVDV: what occurs when exposed in the first 4 months of gestation?
usu causes fetal death and abortion
Depending on time of exposure to BVDV: what occurs when exposed to noncytopathic within 18 to 125 days of gestation to the fetus?
remains persistently infected (PI)
**typically seronegative at birth
**shed BVDV continuously
–> may develop mucosal disease later in lifeform superinfection with cytopathic BVDV
Depending on time of exposure to BVDV: what occurs when exposed at 100 to 150 days of gestation?
Congenitally infected: risk of development of dysplastic lesions:
-teratologic defects in brain, skin and bronchioles
Depending on time of exposure to BVDV: fetuses infected after 150 days have what effects?
**Usually recover without dysplastic lesions
Control measures against BVDV
-killed and MLV vaccinates- avail (not fully controlled with vx)
-elimination of PI animals
-prevention of PI animals being introduced into herd
What is the major lepto serovar associated with abortions in cattle?
Leptospira hardjo
IN cattle, infection with leptospira hardjo is associated with what reproductive effects?
infertility
early embryonic death
abortions from 4 months of gestation to term
birth of weak calves
L interrogans serovar pomona infection in cattle causes abortion in what time period of gestation?
last 3 months of gestation, abortion rate as high as 50%
What are clinical signs of leptospirosis in cattle
icterus
hemoglobinuria
anemia
fever
mastitis: flaccid udder adn thick ropy secretions form all 4 quarters
**cows usually abort without clinical illness
What is grossly seen with leptospira related abortions?
aborted fetus: autolyzed, icteric and edematous
What is seen histologically on the aborted fetus that is seen with leptospira abortions?
renal tubular necrosis accompanied by lymphocytic interstitial nephritis, pneumonia and placentitis
Can leptospira be isolated or demonstrated from fetal tissues?
**rapidly destroyed by autolysis or freezing
-can be isoalted from fetal liver, kidney brain (possible, slow and impracticle)
–> dark field microscopy, FA staining or histo techniques
Leptospira related abortions are typically diagnosed using:
serology: difficult to distinguish among vaccinated, acutely infected and recovered animals
serovar pomona: greater than 1: 12,800 in the dam suggest lepospiral abortion
–> single titers of 1:800 or more in unvaccinated animals, sero conversion or fourfold changes in titers in paired sera indicate lepstospirosis in the herd
Lepto pathophysiology of abortion:
hematogenously spread lepsospires colonized the gravid uterus up tto 142 days after infection
abortion: 1 to 6 wks after L pmono acute dz
abortion: 1 to 3 months with L hardjo
How long can L. hardjo remain in oviducts of infected cows after calving?
up to 22 days
Are aborted tissues infected with leptospira infectious?
-yes to other animals and humans
**handle with caution
What serves as a source of leptospira to other animals?
infected animals shedding organism in urine
In abortion outbreaks with leptospira, what should be performed for treatment and control?
-pregnant cows: vx with killed bacterin and tx with oxytetracycline
-isolated aborting cows from ret of herd
-removed aborted fetuses and placentas from premises
-prevent exposure to swine, rodents and contam water– lessens opportunity for infection
How often is vaccination against leptospira recommended?
6 month intervals or more freq in areas with heavy exposure (dairys and beef operations iwth wet enviroments)
–> aim at reducing urinary shedding and decreasing fetal loss
What is the causative agent of epizootic bovine abortion (foothill abortion) in cattle?
Pajarellobacter abortibovis
Where does Epizootic abortion (Foothill abortion) occur?
syndrome of late abortions in cattle in the foothills bordering the central valley of California
What is required for full development of pathologic changes in the fetus with epizootic abortion (foot hill abortion)?
3 month period
What gross lesions are seen with epizootic abortion (foot hill abortion)?
superficial cervical lymph nodes: up to 16 g
spleen enlarged to 250 g
thymus slightly smaller than normal
+/- enlarged/nodular liver
Pathophysiology of epizootic abortion (foot hill abortion): transmission
soft shell tick: Ornithodoros coriaceus (pajaroello tick)
Pathophysiology of epizootic abortion (foot hill abortion): timing of infection?
b/c at least 90 days are req for development of fetal lesions, infection after 6 months of gestation is not likely result of abortion
Recommended control of epizootic abortion (foot hill abortion)
-exposing heifers to the tick vector before breeding
-changing from spring to fall calving, which takes advantage of limiting exposure ot the last trimester of gestation in some mgmt sys
Brucella abortus pathogen that causes disease:
gram negative coccobacillus that is a facultative intracellular pathogen
Causative agent of Bang’s disease
Brucella abortus
Brucella abortus causes what clinical symptoms in what spp?
Cattle: abortion
Horses: fistulus withers
**zoonotic disease
When does abortion wiht Brucella abortustypically occur?
in the last trimester
Brucella abortus clinical symptoms (esp in a grouped pregnant herd)
lameness
mastitis
epididymitis
and/or orchitis
foul smelling yellow ot brownish exudate containing fibrin and necrotic debris expressed from uterine lumen
placentitis is common findings
Brucella abortus placental abnormalities
-necrotic cotyledons
-intercotyledonary placenta is thickened and opaque with accumulation of odorless, flocculent, yellow-br exudate between maternal and fetal membranes
What are common histopathologic findings on the fetus infected with Brucella abortus
suppurative bronchopneumonia
serositis
lymphoreticular hyperplasia
Brucella abortus diagnosis
culture: B abortus form fetal lung, abomasum or placenta
-Immunoflourescence, PCR
What can be used in adults that are clinically or latently infected with Brucella abortus?
serum agglutiantion
card and buffered plate agglutination
complement fixation
direct & indirect ELISA
Brucella abortus pathophysiology to abortion:
- initial replication in regional lymph nodes
- bacteremia
- colonization of suprammary lymph nodes, mammary gland and gravid uterus
- replication in ER of chorioallantoic trophoblasts & placental endothelial cells and capilllary lumina– assoc with vasculitis and destruction of chorionic villi
- placental inflamm leads to chorioallantoic ulceration, necrosis of trophoblasts, and ulcerative endometritis
- fetal death d/t placental ddisruption and endotoxemia
When does shedding of Brucella abortus occur after abortion?
3 weeks after abortion
Infection with Brucella abortus occurs through what routes?
inhalation or ignestion of bacteria in aborted fetal membranes, fetuses or psot abortion vaginal discharge
Bovine brucellosis has been nearly eradicated in the US by test and slaughter of seropositive cattle and vaccination. However a reservoir remains in what?
bison and elk
**esp in Yellowstone area
Brucella abortus treatment?
comb therapy with on long acting oxytet and streptomycin- may reduce organism
**the infected individuals are usually destroyed
Is there a vaccine for Brucella abortus?
Yes: strain 19 vaccine used as eradication– field strain infected cattle could not be differentiated
Strain RB51– only be administered to young heifers before pregnancy. **can be differentiated from fieldinfected cattle
What is the cause of bovine campylobacteriosis (vibriosis, bovine genital ampylboacteriosis)?
Campylobacter fetus subsp venerealis
Campylobacter fetus subsp venerealis source of infection?
gram eng flagellated bacterium– obligate paarasite of the bovien genital tract
When does Campylobacter fetus subsp venerealis cause abortion in the gestation?
EED or temporary infertility
sporadic abortions in 4 to 8 month gestation possible
What are potential sources for culture of Campylobacter fetus subsp venerealis
-placenta or fetal abomasal contents: req at least 72 hours
-penis or preputial mucosa of infected bulls
**culture is difficult b/c organism is low growing and often overwhelmed by saprophytes
What is the primary reservoir of Campylobacter fetus subsp venerealis?
the bull
Campylobacter fetus subsp venerealis transmission
venereal
Campylobacter fetus subsp venerealis treatment and control
_infected cows usu recover spontaneously w/in 5 months and resist reinfection
-heifers vaccinated with a bacterin before breeding (booster 2 wks later)
-cows and bulls vaccinated annually
Histophilus somni abortion causes what reproductive abnormalities in cattle/
vulvitis
vaginitis
endometritis
weak calf syndrome
stillbirths
occasional abortion
Histophilus somni diagnosis (associated with abortion)
-recovery of lg numbers of organism in rel pure culture form placenta or fetus
-histo evidence of placentitis
-lack fo other apparent causes
Clinical manifestation of Listeria monocytogenes:
encephalitis
abortions
uveitis
septicemia
Listeria monocytogenes bovine abortions occur in what time of gestation?
last 2 months
Listeria monocytogenes sm ruminant abortions occur in what time of gestation?
last month
Listeria monocytogenes aborted fetus lesions
gray-white hepatic foci up to 2 mm in diameter (may be on cotyledone)
exudation occurs between cotyledons
abomasal erosions (reported in aborted lambs)
Listeria monocytogenes death of fetus occurs d/t
placentitis
septicemia
Listerial abortion is experimentally induced in cattle and sheep after how many days of infection?
cattle: 6 to 8 days
sheep: 3 to 11 days
outbreak of Listeria monocytogenes have been associated with what?
feeding silage
Which mycoplasma spp have been associated with abortion in cattle and goats?
Cattle: Mycoplasma bovis (primarily), M. bovigenitalium
Goats: Mycoplasma mycoids subsp mycoids and Mycoplasma capricolum subsp capricolum
Mycoplasma bovigenitalium causes the what lesions?
granular vulvovaginitis
less commonly endometritis
Treatment of Mycoplasma
tetracycline, florfenicol or macrolide antibiotics may limit losses in pregnant animals if lesions of vulvovaginitis are seen in herdmates
What organism has been recovered from embryo flushing media and has been associated with granular vulvitis and abortion in cattle?
Urea plasma (U. diversum)
Bovine infection with ureaplasma diversum is common, but abortions are rare. What is a preventative measure that can be taken to prevent contamination during an embryo flush?
Uterine contamination can be avoided by using a doube-rod technique for AI
Many bacteria are ubiquitous, freq contaminate aborted fetuses and placentas, and should not be considered the cause of abortion unless:
- they are isolated form the placenta and fetus in large numbers and relatively pure culture
- Placentitis or fetal inflammation is evident
- other more likely causes of abortion have been eliminated
Trichomoniasis is caused by
Tritrichomonas foetus
Tritrichomonas foetus is what kind of organism?
flagelled protozoan
Where is Tritrichomonas foetus found?
in the prepuce, penis and occasionally urethral orifice of infected bulls
Tritrichomonas foetus transmission occurs via
venereal, transmission to cows results in clinical disease
Tritrichomonas foetus infertility is characterized by:
-high percentage of cows returning to estrus or found nonpregnant after breeding season
-cows calving late
-occasional pyometras and abortions
Diagnosis of Tritrichomonas foetus in the female
culturing trichomonads or using PCR to detect placental fluids or fetal abomasal contents
Diagnosis of Tritrichomonas foetus in males
preputial smegam collected by using a plastic pipette or commerically available sampling device against mucosa
What can lead to false negative results on culture and PCR for Tritrichomonas foetus?
-T. foetus degrades its DNA postmortem, improper sample handling male lead to false negative results
After cows are infected with Tritrichomoniasis foetus and EED occurs, does immunity develop and if so, how long?
Yes
Develops for a 2 to 6 month period of immunity to reinfection
Can bulls clear infection with Tritrichomonas foetus?
No, typically permanently infected in bulls >3 to 4 years old
Younger bulls, may be transiently infected (related to development of deeper mucosal folds in prepuce)
Treatment of cows infected with Tritrichomonas foetus
-usually clear infection within 95 days, rarely persists past 6 months
-no tx available in US
-cull infected animals OR
3 months of sexual rest
Is vacccination effective against Tritrichomonas foetus?
No
The recommendation is to test bulls over 3 years of age and cull
What is the definitive host of Neospora caninum?
canids– shed oocyts in feces after ingeted of infected tissues from intermediate hots
Neospora caninum intermediate hosts:
cattle
deer
suspect birds and rodents (not been demonstrated)
Neospora caninum mode of transmission
-vertical: dam to fetus in utero
-point-source horizontal: ingestion of feed contaminated with feces containing oocyts
horizontal transmission does not exist
Bovine fetal lesions caused by Neospora caninum
-nonsuppurative encaphlitis with foci of necrosis and gliosis
-suppurative myositis
-heaptitis
-myocarditis
**lesions are distinctive
Neospora caninum abortions occur in what time period of gestation?
mostly in early 2nd trimester
**may occur throughout gestation
Neospora caninum Diagnosis
-characteristic lesions of aborted fetuses
-seroepidmeiologic study of equal aborting and nonaborting hermate cows if proprotion of seropos is statically higher in those that have aborted
Does finding a cow that is seropositive for Neospora caninum, confirm that is a cause of abortion?
No
**cows that abort are not protected form future abortion by this organism
Sarcocystosis can cause abortion in what spp? and with what Sarcocystis
cattle: Sarcocystis cruzi
sheep: Sarcocystis ovicanis
goats: Sarcocystis capracanis
Do cattle show C/S of infection with Sarcocystis?
No, unless massive or repeated infection C/S:
-depression, anorexia, wt loss, lameness, hair loss, emaciation or death
Sarcocystis abortions occurs in what time of gestation?
late gestation
Sarcocystis diagnosis
-no specific gross lesion in aborted fetus
-histo: +/- protozoa observed in villi and sm arteries of cotyledon or (more likely) the caruncle; more likely to be seen in fetal brain that other tissues
-nonsuppurative inflamm: in placenta or fetal tissues (brain, heart, lung, liver or kidney)
What is the pathogenesis of abortion caused by sarcocystis?
unknown - generally numerous spores are required to induce abortion experimentally
Sarcocystis can be recovered from what organs in cows, generally no assoc with lesions or clinical evidence of illness?
skeletal and cardiac mm
Control of Sarcocystis infection?
-life cycle to be broke: feeds should be kept free of dog or cat feces
-carnivores should not be allowed to eat aborted fetuses, placentas or other ruminant carcasses
Bluetongue belongs to what genus of viruses?
orbivirus
Blue tongue can result in what reproductive lesions in sheep, cattle or other ruminants?
EED, abortion, fetal anomalies
Border disease or hairy shaker disease is an ovine pestivirus that can cause what reproductive lesions?
embryonic and fetal death
still births
dysplasia of the CNS, skeleton and fleece
birth of weak lambs with low viability
Coxiella burnetii is what kind of bacteria?
obligate intracellular, pleomorphic bacterium– related to rickettsial family of bacteria
What is the causative agent of Qfever (dz of humans)?
Coxiella burnetii
Coxiella burnetii causes abortion in what time period of gestation?
late term abortions in sheep and gats (rare in cattle)
Coxiella burnetii: what spp is the primary reservoir?
subclinically infected ruminants
Coxiella burnetii history/presentation?
late term abortions or delivery of stillborn or weak kids/lambs in affected her or flock
Coxiella burnetii placental lesions
thickened white or chalky plques and red-brown exudate, esp in intercotyledonary areas
Coxiella burnetii Diagnosis of abortion
-gross and histo evidence of severe placentitis with lg numbers of organisms visible using modified Koster stain, Stamp’s modified Ziehl Neelsen stain or Gimenez stain
-demonstration of compatible placental lesions
-quantification of C. burnetti by qPCR
-documentation of the absence of other abortigenic agents
Coxiella burnetii is culture possible?
Yes, but is difficult
Is Coxiella burnetii from normal ruminants?
Yes in small numbers
**seropos/seroneg small ruminnts shed the organism
Coxiella burnetii transmission
-inhalation or ingestion of infected material
-spread by infected ticks
Coxiella burnetti pathophysiology
-inhalation/ingestion/spread by ticks
-replicates in trophoblasts–> placentitis with late stage abortion, stillbirth or birth of weak offspring
Coxiella burnetii can persist in the environment as
small cell variant: durable sporelike particle
What are recommendations due to Coxiella burnetii zoonotic potential?
-pregnant women, immunosuppressed individuals, indivuals with preexisting illness and those with veiscular grafts should not handle Coxiella infected animals or tissues or be exposed to contaminated environments
What is the most common means by which humans become infected with Coxiella burnetii during ruminant abortion outbreaks?
Aerosolization and inhalation of SCVs
Treatment and control measures for Coxiella burnetii
-aborting does and ewes isolated
-abortuses and palcentas removed from premises; disposal: burial, burning or composting
-no Tx available for ruminants (oxytetracycline suggested)
-vaccine not avail in US
-cleaning and disinfection contam bedding
-PPE
abortion causes by campylobacter fetus subsp fetus causes abortion in ewes in what time period of gestation?
last 6 weeks of pregnancy
campylobacter fetus subsp fetus infection of ewes causes what reproductive lesions
still births
birth of premature lambs
necrosuppurative placentitis and multiorgan infection of fetus
–> fetus edematous and has pot-bellied appearance
campylobacter fetus subsp fetus infected ewes may show what C/S before parturition
fever
diarrhea
depression
vaginal discharge
What lesions are seen in the ovine fetuses aborted due to campylobacter fetus subsp fetus?
multifocal, circular, pale foci (resembling donuts/targets) visible on liver of 25% of aborted vine fetuses
**not pathognomonic, but strongly suggestive of campylobacter fetus subsp fetus
Transmission of campylobacter fetus subsp fetus
Transmitted via ingestion
campylobacter fetus subsp fetus Pathophysiology
- ingested
- translocated across intestinal mucosa into blood stream
- infects placenta and fetus
campylobacter fetus subsp fetus incubation period
highly variable
12 to 113 days (most common 14 to 21 days)
campylobacter fetus subsp fetus fetal infection most common in what time period of gestation?
last 2 months of gestation
campylobacter fetus subsp fetus abortion outbreaks tend to be in what time period/ yearly cycles?
every 4 to 6 year cycles
campylobacter fetus subsp fetus abortion outbreaks can be treated with:
tetracyclines or macrolides
campylobacter fetus subsp fetus: treatment/diagnosis: why is speciation important?
C jejni (N. American strain) vs C. fetus subsp fetus cannot be distinguished
Campylobacter jejuni is an enteric pathogen that causes enteritis and diarrhea in many spp. Only in sheep does it cause, what reproductive abnormalities?
placental and fetal infection (common)
Campylobacter jejuni pathophysiology in ewes
IV ioculation of pregnant ewes with C. jejni at 114 to 123 days of pregnancy consistenty induced abortion at 7 to 12 days later
Campylobacter jejuni aborted tissues from sheep should be handled with care because
These are infectious to humans
Brucella ovis manifests primarily as what?
epididymitis in rams
Ewes seldom show clinical evidence of infection– late abortions, still births and delivery of weak lamns (RARE)
Is Brucella ovis a zoonotic pathogenic?
Not been documented to be zoonotic
Chlamydophila abortus Abortion (Enzootic Abortion of Ewes) is what kind of bacteria?
gram negative obligate intracellular bacteria
Ovine chlamydial abortion is called
enzootic aboriton of ewes
What are characteristic findings of Chlamydophila abortus are
late term abortions or stillbirths with placentitis
Chlamydophila abortus with abortions, does the dam show C/S
No, but may have serosanguineous vaginal discharge several days before and after parturition
What is the most consistent necropsy finding in chlamydial abortions?
placenta markedly thickened with necrosis in cotyledon and intercotyledonary areas
hemorrhagic exudate may be evident at edges of these lesions
Chlamydophila abortus diagnosis of abortion
-ID of organism:
-placental impression smears stained with GIemsa, Gimenze or modified Ziehl Neelsen– spheric bodies in cytoplasm of trophoblasts
-presence of placental lesions
Chlamydophila abortus transmission
ingestion, shed from genital tract of infected animals before and after parturition
Chlamydophila abortus source of infection
reside in intestinal tract
exposure to aborted tissues, contaminated environment or vaginal discharge
Chlamydophila abortus incubation period
60 to 100 days
Is Chlamydophila abortus zoonotic?
Yes, pregnant women, or immunosuppressed individuals should not handled infected animals or tissues
PPE should be worn
Toxoplasmosis gondii is what kind of organism
ubiquitous protozoan
Toxoplasmosis gondii transmission to sheep and goats
via direct contat or fectal contamination of feed or water
**ingestion of oocysts in feline feces
Toxoplasmosis gondii Cats are infected and shed when
infected by ingestion of infected rodents, birds, carrion or aborted fetuses and tissues
The cats shed heavy numbers of occysts in first 2 to 4 weeks after becoming infected
Toxoplasmosis gondii Clinical illness in adults?
No, but may result in EED, fetal death and abortion, stillbirth or birth of weak nonviable lambs or kids
Toxoplasmosis gondii characteristic gross lesion
presence of white chalky foci necrosis and calcification up to 2 mm in diameter in cotyledons
Toxoplasmosis gondii histo lesions
nonsuppurative encephalomyelitis
+/- pneumonia, myocarditis, hepatitis
Toxoplasmosis gondii tachyoites- what are they and where can they be found in aborted material?
placenta or other fetal tissues (not numerous)
Tachyzoites- oval with a central nucleaus and appear larger in impression smears than in paraffin sections
Toxoplasmosis gondii diagnosis
serologic tests: modified agglutination test, indirect FA test, Sabin Feldman dye test, indirect hemagglutination test, ELISA– detect in pleural fluid or amniotic fluids or presuckling serum from nondecomposed fetuses
Toxoplasmosis gondii high maternal plasma titers interpretation
not diagnostic of toxoplasma abortion, but lack of titer eliminates toxoplasmosis as the cause of abortion
Toxoplasmosis gondii when does placental infection occur
approx 14 days after ingestion of oocysts
Toxoplasmosis gondii what lesions are seen in what time period of gestation after infection
infection after 50 days gestation– EED and resorption
infection between 60 to 100 days– fetal death or birth of weak lambs
infection in last month of gestation: the no apparent effect on fetus
**experimental infection between 6 to 14 days of pregnancy, abortions occurred 1 to 2 months after inoculation
**natural infection abortions 1 month before parturition
The incidence of abortion in llamas and alpacas is low– Infectious casues in North America include:
Leptospirosis
toxoplasmosis
chlamydophilosis
other nonsp uterine infections
BVDV– considered emerging dz in alpaca herds
