Infectious Causes of Abortion

What side is the caruncle on?

Maternal

What side is the cotyledon on?

Fetal side

What abortion rates are normal?

5% is common

<5% is good

<2% is excellent

What is the most common cause of abortion?

Chlamydophilia abortus

What causes enzootic abortion?

Chlamydophilia abortus

T/F Chlamydophilia abortus is zoonotic?

True

What does Chlamydophilia abortus cause?

If naive: 25-60% abortion storms

If endemic: 1-15%

Causes persistent subclinical infection in nonpregnant and multiparous sheep and goats

How is Chlamydophilia abortus transmitted?

Oronasal contact with aborted tissues, vaginal discharge, feces, or contaminated neonate

Maybe pigeons or sparrows, ticks, insects, or venereal

What is the lifecycle of Chlamydophilia abortus?

Biphasic

When outside the cell it is metabolically inactive as an elementary body

Once ingested it enter the tonsils and are endocyted into a vacuole and inhibits lysosomes

The elementary body then becomes and active reticulate body and divides

How does Chlamydophilia abortus cause abortion?

It moves to the cotyledonary but dont begin rapid replication until 115 days in gestation then placentitis prevents nutrient transfer and casues death

How do you diagnose Chlamydophilia abortus?

PCR of placenta, vaginal swabs of female is best

Can do impression smears

Serology is possible but can cross react with Chlamydia pecorum

Describe the vaccine for Chlamydophilia abortus?

Does not prevent shedding at lambing and will reduce but not prevent all abortions

Only labeled in sheep

How do you prevent Chlamydophilia abortus?

Females shed for 3 weeks so isolate infected one

Can cull ewes and does that have aborted

Burn/bury aborted tissues

What is Chlamydophilia abortus often dual infected with?

Coxiella burnetii in goats

How do you treat Chlamydophilia abortus?

Oxytet in feed used to be used but there are not longer legal VFD label for this

Need to do injectable oxytet and abortions will still occur but will be less than if not treating the herd

What does Chlamydophilia abortus cause in humans?

Abortions. Pregnant women should not work with sheep and goats around kidding

Causes influenza like symptoms

What causes Q fever?

Coxiella burnetti

What does Coxiella burnetii cause?

Intracellular bacteria that persists in ticks but does not need them to transmit

Small cell variant survives in the environment for a very long time

Highly infectious at low doses

T/F Coxiella burnetii is zoonotic?

True

How is Coxiella burnetii transmitted?

Inhalation of spore contaminated dust

Contact with mucus membranes

Tick transmission from bites or eating their feces

What are the reservoirs for Coxiella burnetii?

Cattle, sheep, goats, cats, dogs, rabbits, rodents, birds, ticks

Shed in urine, feces, milk, aborted tissues, vaginal secretions

How long do females shed Coxiella burnetii?

Shed organisms for up to 4 months in vaginal secretions and milk

5 months in feces

How do you diagnose Coxiella burnetii?

PCR of the placenta (always tell owner to save placenta)

Histology of placenta is ok

Serum only indicates recent infection

What are some lesions caused by Coxiella burnetii?

White areas of necrosis on cotyledons

Thickened intercotyledonary areas

Mineralization

How do you treat Coxiella burnetii?

No vaccines in US

Oxytet can prevent abortion but not shedding. Once infected can be carriers for life

How do you control Coxiella burnetii?

Isolate aborted females

Can cull if prevalence is bad due to chronic shedders

Can treat environment with lime of calcium cyanide

Control cats and rodents

What does Coxiella burnetii cause in humans?

Flu like symptoms

Chronic infections like endocarditis, hepatitis, undulant fever, atypical pneumonia

What ppe can you use for Coxiella burnetii?

Sleeves when assisting with birthing or handling placenta or abortus

Wear masks when cleaning livestock reside

Vaccination high risk humans

How do you diagnose Campylobacter?

Culture from fetal tissues and vaginal discharge (can be resistant to tet and penicillin)

25% of fetuses have target lesions

NO PCR

How do you treat Campylobacter?

Oxytet

Vaccination of pregnant animals

How is Toxoplasma gondii transmitted?

Shed in cat feces and infective for 18 months

Cats are only definitive host but all warm blooded animals can be intermediate hosts

What are the developmental forms of Toxoplasma gondii?

Tachyzoite

Bradyzoite

Sporulated oocyst-containing sporozoites

What are the C/S of Toxoplasma gondii?

Dam is asymptomatic

Fetus is mummified or macerated

How do you diagnose Toxoplasma gondii?

Multifocal areas of necrosis on cotyledons with no inflammation

PCR of fetal tissues

Serology is also possible

What is the preferred method for diagnosis of toxo if placenta is unavailable or necrosed?

Toxoplasma antibody in fetal fluids

How do small ruminants get toxo?

Environmental contamination

How do you control toxo?

Prevent cats from the area

How do you treat toxo

Decoquinate during pregnancy (not in dairy animals)

Monensin

What is required for vertical toxo transmission?

Immunosuppression

What does toxo cause in humans?

Neruo defects and blindness in infants

Encephalitis if immunosuppressed

How do humans get toxo?

From undercooked meat

• Cook meat to 150 F

• Freeze meet to 10.4 for 1 day

What cases Hairy-shaker?

Border disease virus, and BVDV-1

What is the reservoir for border disease virus?

Sheep, goat, cattle PI animals

What are the lesions of border disease?

Acute necrotizing placentitis

• If severe fetal death and absorption

• If not severe lesions heal

• Fetal consequences depend on stage of gestation

How do you control border disease virus?

Eliminate PI animals

No vaccine

Test and quarantine new additions

Where do we have bluetongue?

Endemic in south and western US

How is bluetongue transmitted?

Arthropods in the late summer and fall

T/F bluetongue is zoonotic?

False

What animals can get bluetongue?

Sheep, wild ruminants, cattle, goats

What are the C/S of Chlamydophilia abortus?

Transient fever and lethargy at initial exposure

2 days prior to abortion then a mild and transient pneumonia and hepatitis, anorexia, vaginal bloody discharge

What can the fetuses look like after Chlamydophilia abortus?

Fresh, autolyzed, can be mummified, can have weak newborns

Retained placentas is possible

When do most Chlamydophilia abortus abortionsoccur?

Usually after 100 days, but can early embryo death can occur

What happens after a female aborts once from Chlamydophilia?

They are protected for 3 years but will shed

T/F venereal is a major transmission way for Chlamydophilia abortus?

False

What does Chlamydophilia bortus cause in bucks and rams?

Orchitis and seminal vesiculitis

What are the lesions of Chlamydophilia abortus?

Placenta lesions vary a lot but necrosis or thickening is common

Sometimes nothing on fetus

What is Chlamydophila pecorum?

Can cause abortion but usually arthritis, KCS, respiratory disease

What are the outcomes of Coxiella burnetii for offpsring?

Abortion in 3rd trimester

Stillborn full term offspring

Weak full term offpsinrg

What can females do before abortion with Coxiella burnetii?

ANorexia or depression 1-2 days before

T/F Coxiella burnetii provides immunity after?

False, need to cull all infected animals

How does Coxiella burnetii cause abortion?

Infect macrophages and disseminate to placenta leading to abortion

T/F Coxiella burnetii is zoonotic?

True

What causes vibriosis?

Campulobacter

What campylobacter cause abortion?

jejuni

fetus subsp fetus

What is the #1 cause of abortion in US sheep?

Cambylobacter (Vibriosis)

T/F Campylobacter is zoonotic?

True

What is Campylobacter?

Commensal in intestines and gallbladders

Confined ewes are at increased risk

T/F Campylobacter can be transmitted venereally?

False

When does Campylobacter cause abortions?

Last 6 weeks of gestation can also cause stillbirths or weak lambs (in infected 2 weeks before parturition)

How can you control campylobacter?

Vaccine. Give 1 dose before breeding and booster in 2-3 months

VFD label for Chlortetracycline

What happens after Campylobacter infects a ewe?

Long lasting immunity even if they did not abort. Can expose non-pregnant animals to aborted animals

What does campylobacter cause in humans?

Mild gastroenteritis

What is the life cycle of Toxo?

1. Nonimmune cat ingests bradyzoites from cysts in animals

2. In 3-15 days bradyzoites undergo gametogny in cats and are shed in feces

3. Oocysts sporulate in 1-5 days in feces then are infective

4. Next animal eats those and get infected

5. Infects female caruncles first then cotyledons

What are the effects of toxo on the fetus?

1st 40 days of gestation: EED

40-120: fetal mummification, maceration, or abortion

after 120: abortion, premature, stillborns, weak offspring

If before gestation no effects on pregnancy

What is the most important reservoir for border disease virus?

PI sheep and goat or cattle

How is BDV secreted?

Placenta, saliva, urine, or feces

How does BDV cause viremia?

Infects macrophages and lymphocytes

How is most BDV trasnmitted?

Vertical

What happens to ewes infected with BVD <60 days?

Most die but some can create shaker or hairy limbs and are PI animals

What happens to ewes infected with BVD 60-85 days old?

Unpredictable, some are PI some are not

What happens to ewes infected with BVD after 85 days?

Immunocompetent will not be viremic and antibody positive

What are C/S of BDV in a herd?

Febrile newborns

Increased number of open females (EED)

Mummified fetuses

Poor doing lambs

What happens if a lamb survives BDV?

Can look normal after 20 weeks

What do goat kids that get BDV look like?

Normal hair

Fetal mummification and abortion

Hypomyelination of spinal cords

How do you test for BDV?

Fluorescent antibody testing is most accurate

PCR fetal tissues also works

No antibodies in PI animals

IHC notches not as good as in cattle but can work

What is the reservoir for bluetongue?

Cattle

When is bluetongue teh most prevalent?

Late summer early fall due to high numbers of Culicoides

What is the incubation for bluetongue in sheep?

3-7 days

What are the C/S of bluetongue in sheep?

Vasculitis causing swollen tongue, oral lesions, abortion, cyanotic tongue, petechia

what causes abortion in bluetongue?

Hepatic necrosis, skeletal deformitites

What do you need to rule out in suspected bluetongue?

Plant toxicity and Cache Valley fever

How do you diagnose bluetongue?

Virus isolation using whole blood EDTA, usually from ewe

PCR

Serology also work

How do you prevent bluetongue?

Vaccines but there are lots of strains and risk for mutations

Try to control nats and keep away from wet areas

When do you vaccinate for bluetongue?

2 weeks before breeding (live attenuated)

Vaccinating rams can reduce fertility transiently