Small Ruminant - Abortions Flashcards
Greater than what percentage of abortion loss need to be investigated?
> 2% loss
Abortion storms can happen with what percentage of loss?
> 30% loss
When during gestation do most infectious causes lead to abortion?
> 100 days gestation
True or False: Most bacterial causes of small ruminant abortion are zoonotic.
TRUE
What are the most common bacterial causes of small ruminant abortion?
Campylobacter (sheep) and Chlamydia abortus (enzootic abortion of sheep)
What are some other bacterial causes of abortions in small ruminants?
Salmonella, Listeria, Brucella, Coxiella, and Leptospira
What protozoan is responsible for abortions in small ruminants?
Toxoplasma gondii
What viruses are responsible for abortions in small ruminants?
Cache valley virus, Border disease, BTV, Akabane, Schmallenberg virus, CpHV 1
True or False: Campylobacter is not zoonotic.
FALSE
What are the etiologic agents of Campylobacter abortions?
Campylobacter fetus subsp. Fetus, C. jejuni, C. lari
How is Campylobacter spread?
oral transmission
Campylobacter causes cyclic and epizootic abortions in sheep or goats?
sheep
When do abortions occur in relation to infection of Campylobacter?
10-20 days post infection
What does the placenta look like in sheep with campylobacter?
hemorrhagic necrotic cotyledons and edematous or leathery intercotyledonary areas
What will the fetus look like in campylobacter abortions?
Autolyzed with necrotic foci in the liver (target lesions)
How are campylobacter infections treated in pregnant ewes?
tetracyclines
How is campylobacter prevented?
vaccination (6-8 weeks prior to breeding) and hygeine
True or false: Chlamydia abortions are zoonotic.
TRUE
Do chlamydia abortions affect goats or ewes?
both
What Chlamydia species are responsible for causing abortions?
C. abortus or pecorum (aka psittaci)
Chlamydia does not only cause abortions, what else can it cause to the fetus?
stillborns and weak offspring
When does Chlamydia effect the fetus in regards to infection?
60-90 days after infection
Chlamydia is responsible of up to ___% of abortions.
60 percent
True or False: Aborted fetuses have pathognomonic lesions that are similar to those of Campylobacter.
False - aborted fetuses typically does not have any gross lesions and diagnostic samples are unrewarding
What does the placenta look like in goats and ewes with Chlamydia infection?
Necrotic, red-brown cotyledons and thickened intercotylendonary areas with exudate
Do ewes typically abort again? Do they continue to shed?
Ewes do not abort again however they are persistently infected and can shed
If ewes are infected late (>100 days of gestation) what are they at risk for?
abortion during the next gestation
True or False: Chalmydia can be transmitted venereally from the ram.
TRUE
How is chlamydia infection treated?
Tetracyclines
How are Chlamydia infections controlled?
Isolation for 3weeks to 3 months and vaccination (sheep)
True or False: Toxoplasma abortions are zoonotic.
TRUE
What is the etiologic agent of Toxoplasma abortions?
T. gondii
True or False: Toxoplasma abortions are a major cause of ovine and caprine abortions throughout the world
TRUE
How is toxoplasma transmitted?
ingestion of sporulated coccidian oocytes from kittens
If a goat or sheep is infected with Toxoplasma prior to breeding what occurs?
Immunity with no clinical signs
If a goat or sheep is infected with Toxoplasma early in gestation (30-90 days) what occurs?
resorption and mummification
If a goat or sheep is infected with Toxoplasma during mid gestation (40-120 days) what occurs?
mummification, maceration, and abortions
If a goat or sheep is infected with Toxoplasma during late gestation what occurs?
abortions, prematurity, stillborn, weak, and perinatal death
What does the placenta look like in Toxoplasma infected small ruminants?
white necrotic/calcified foci on cotyledons
Where else can Toxoplasma cause lesions in small ruminants? What lesion?
Brain - focal suppurative inflammation
In cases of immunity, what type of transmission is possible?
transplacental transmission
Goats/Sheep are typically more susceptible to Toxoplasma infection, but have better resistance to reinfection.
goats
How is Toxoplasma transmission prevented?
Control cat population (prevent cats from lactating or giving birth on feed) and give coccidiostats
Cache Valley virus causes abortions in sheeps or goats more?
sheep
How is Cache Valley virus transmitted?
Vector (Culicoides and mosquitos) blood borne
What happens if a ewe or goat is infected in early pregnancy with Cache Valley virus?
Embryonic loss (<32 days), mummification, and deformities
What deformities are associated with early gestation Cache Valley virus infection?
arthrogryposis, scoliosis, torticollis, muscle atrophy, and head
What happens if a ewe or goat is infected in late pregnancy with Cache Valley virus?
abortions and stillborns
How is Cache Valley virus diagnosed?
Subclinical exams, serology, and rule out other arthrogryposis causes
How is Cache Valley virus treated?
There is no treatment
How do you prevent Cache Valley virus infections?
Breed outside vector season and control vectors
What plant can cause abortions in small ruminants?
Veratrum californicum
What is the toxin that Veratrum californicum releases?
cyclopamine
What will you see if a dam ingests Veratrum californicum <10 days into gestation?
Early embyronic death
What will you see if a dam ingests Veratrum californicum 11-16 days into gestation?
Cyclops appearance, anopthalmos, and cleft palate
What will you see if a dam ingests Veratrum californicum 25-36 days into gestation?
Hypoplasia of the metacarpals and metatarsals
What else can Veratrum californicum affect in the fetus?
The fetal pituitary gland development
