28: Abortion 2

The “Three C’s” of abortions in animals

Chlamydia, Campylobacter, and Coxiella burnetii

Most common manifestations of the three C’s of abortion

Subclinical :(

What determines whether an abortion pathogen (or any pathogen) is endemic or epidemic

Amount of herd immunity; high immunity makes it endemic, low immunity makes it an epidemic

Species most affected by Chlamydia abortus

Small ruminants, esp goats

What type of bacteria is Chlamydia

Obligate intracellular bacteria

Life cycle of Chlamydia spp.

Metabolically dormant elementary body infects a host cell → elementary body turns into an active and replicating reticulate body → converts back to inactive elementary body to infect other cells

Antibiotic class of choice for active Chlamydia infections

Tetracyclines

Why are Chlamydia infections hard to clear

Because of “latent” periods where the elementary body predominates

Transmission for Chlamydia

Direct contact with any reproductive or fetal tissues/fluids

CS associated with all three “C’s” of abortion

Placentitis

When do we see chlamydial abortions

Late term (essentially a stillbirth)

What happens if a female is exposed to Chlamydia in the last month of gestation

It will go latent and will cause abortion the following year

T/F: after animals have a chlamydial abortion, they develop immunity

True, but they will shed it again during periods of stress

Best samples to submit for abortion testing

Placenta and whole fetus on ice

How long should an animal be isolated after a (potential) chlamydial abortion

3 weeks

T/F: Chlamydia abortus is zoonotic

True

What does Chlamydia abortus cause in humans

Influenza-like illness and pregnancy complications

What type of bacteria is Coxiella burnetii

G- obligate intracellular rickettsial

Life cycle of Coxiella burnetii

Metabolically dormant small cell variant infects a host cell → small cell variant turns into an active and replicating large cell variant → converts back to inactive small cell variant to infect other cells

Why is Coxiella burnetii such a scary pathogen

• Survives for degades in dust

• VERY low infectious dose

• Aerosolized transmission across far distances

Species that are most likely to be infected with Coxiella burnetii

Small ruminants again :)

Transmission for Coxiella burnetii

Primarily aerosolized, but basically any route and from any bodily secretion

T/F: Coxiella burnetii is reportable

YES

When do we see abortions with Coxiella burnetii

Late term abortion/stillbirth

What does Coxiella burnetii cause in people

Q fever

When is shedding highest for Coxiella burnetii

2 weeks post abortion or post-partum

Sample needed for diagnosis of Coxiella burnetii

Placenta

Treatment for Coxiella burnetii

None, treatment doesn’t do anything

Specific causative agent of Bovine Genital Campylobacteriosis

Campylobacter fetus subsp. venerealis, fetus, and others

Primary transmission for Campylobacter fetus

Venereal

When do we see abortions caused by campylobacteriosis

Embryonic death and early abortions

What other disease does Bovine Genital Campylobacteriosis look a lot like

Tritrichomonas

How responsive is Campylobacter fetus to treatment

Very, it is easy to clear

Why does Campylobacter fetus need specific media for testing

It wants to die as soon as you collect a sample

Source of most Campylobacter fetus infections

Asymptomatic older bulls

CS of Campylobacter fetus in cows

Mucopurulent endometritis and early embryonic death

Where do older bulls harbor Campylobacter fetus

Deep preputial crypts

What age of bulls can potentially be treated for Campylobacter fetus and why

Bulls <4 years old; their penile epithelial crypts are poorly developed, and they get transient infections instead of permanent infections

Diagnosis for Campylobacter fetus in bulls

Preputial cavity scraping (for culture?)

Diagnosis for Campylobacter fetus in cows

Vaginal mucus agglutination test

Treatment for Campylobacter fetus in cows

None, they usually clear it or don’t regardless of what we do

Treatment for Campylobacter fetus in bulls

We typically don’t, but you can try streptomycin if you have a valuable, young bull

CS of Campylobacter fetus in small ruminants

Late term abortions

Fetal lesions characteristic of Campylobacter fetus in small ruminans

Umbilicated hepatic lesions

Causative agent of Epizootic Bovine Abortion, AKA Foothill Abortions

Pajaroellobacter abortibovis

Transmission for Epizootic Bovine Abortion

Pajaroello tick

Geographic distribution of the pajaroello tick

Sierra Nevadas

When does a cow have to be bitten by a pajaroello tick to experience CS

Months 2-6 of gestation

CS associated with Epizootic Bovine Abortion

Late term abortion or weak calf

Primary fungal cause of mycotic abortions

Aspergillus

When do fungal abortions typically happen

Third trimester

Route of exposure for mycotic abortions in food animals

Inhaled or ingested → hematogenous spread

Route of exposure for mycotic abortions in horses

Ascending infection

Lesions associated with mycotic abortions

Thickened, leathery cotyledons and intercotyledonary space and fungal plaques

Most common bacterial isolates associated with Equine Endometritis

Streptococcus equi zooepidemicus and E. coli

Most common fungal isolates associated with equine endometritis

Candida and Aspergillus

Demographic at an increased risk of early embryonic loss from equine endometritis

“Dirty” mares that have persistent microbiota after breeding

Diagnosis for equine endometritis

Culture

Equine abortion disease that is a foreign animal disease and is reportable

Contagious equine metritis

Causative agent of contagious equine metritis

Taylorella equigenitalis

Where is contagious equine metritis endemic

Europe

Demographic for contagious equine metritis

Top performance horses that travel

CS of contagious equine metritis in mares

THICK mucopurulent vaginal discharge

CS of contagious equine metritis in stallions

Asymptomatic carriers :(

Protective measures taken for horses that are positive for contagious equine metritis

Extended quarantine