Unit 2 - Small Ruminant Reproductive Flashcards
What is the most common diagnosis for abortions?
Unknown cause
What percentage of ovine abortions have a diagnosed cause?
30-50% - 70-80% of which are infectious
What are the ‘three’ most common causes of abortion?
Campylobacter jejuni and C. fetus
Toxoplasma gondii
Chlamydia abortus
When diagnosing the cause of abortion in small ruminants, what samples are important to submit?
The fetus and the placenta
What is the most common Campylobacter species that causes abortion in the US?
C. jejuni
What are the two strains of C. jejuni that cause abortions?
Hypervirulent and Sheep abortion
Where is C. jejuni carried?
In the intestinal tract
How is C. jejuni transmitted?
Fecal-oral
Is Campylobacter abortion more common in sheep or goats?
Sheep
T/F: Sheep show non-specific signs of disease when infected with Campylobacter.
False - there are no premonitory signs of disease; the ewe isn’t sick
When does Campylobacter abortion happen?
In the last 6 weeks of gestation
What is the pathogenesis of Campylobacter abortion?
Campylobacter colonizes in the intestines and causes bacteremia. Bacteria gets to the placentomes resulting in placentitis and fetal infection
What placental lesions does Campylobacter cause?
Non-specific: Yellowish foci on cotyledons to yellowish exudate covering the whole cotyledon
What other lesions does Campylobacter cause?
Necrotic foci on the liver in 40% of aborted lambs
Generalized autolysis of the fetus and blood-tinged edema
How is Campylobacter diagnosed?
Gross liver lesions
Darkfield or phase contrast of cotyledons, fetal stomach contents, and vaginal discharge
Culture
FA or IHC in some labs
What is the ‘treatment’ for Campylobacter abortion?
Draxxin or other long-acting macrolides
How do you prevent Campylobacter infection?
Do not mix ewes when they are pregnant
Immunization
What species of Campylobacter do its bacterins contain?
C. fetus ss fetus and C. jejuni
What is the protocol for Campylobacter immunization in ewe lambs and previously unimmunized ewes?
One dose pre-breeding
Second dose at 3-4 months of gestation
What is the protocol for Campylobacter immunization in previously immunized ewes?
One dose at 3-4 months of gestation
What is the etiologic agent of enzootic abortion?
Chlamydia abortus
When does infection for enzootic abortion occur? From what?
At any time from fecal-oral or from aborted fetus
What is the pathogenesis of enzootic abortion?
The organism usually stays in the intestine until the last trimester. During the last trimester, the organism enters the blood stream and infects the fetus.
Abortion typically occurs 30-40 days following infection (in pregnant ewes)
T/F: If a pregnant ewe is infected from an aborted fetus/vaginal discharge, she usually does not abort until the subsequent pregnancy.
True
Ewes and does may have _____ discharge 2-3 days before aborting due to Chlamydia.
yellowish
What does a Chlamydia infected placenta look like?
Cotyledons are necrotic, gray-brown in color with areas of leathery consistency
What lesions does Chlamydia cause in aborted fetuses?
Focal necrosis, hemorrhage, enlarged lymph nodes, ascites, and increased pleural fluid
Not pathognomonic
How is Chlamydia diagnosed?
Gross lesions Exfoliative cytology IHC of impression smears or sections of cotyledons IIFA Serodiagnosis Culture
How do you treat/prevent chlamydia infection?
Feed tetracycline during the last semester
Immunization - killed bacterins in the US
Where is Toxoplasma gondii harbored?
In cats
Clinical signs/lesions from T. gondii are dependent upon when the fetus was infected. What occurs if the fetus is infected at 0-2 months?
Fetus is resporbed
Clinical signs/lesions from T. gondii are dependent upon when the fetus was infected. What occurs if the fetus is infected at mid-gestation?
Abortion
Clinical signs/lesions from T. gondii are dependent upon when the fetus was infected. What occurs if the fetus is infected in the last trimester?
Mummies, stillbirths, and weak lambs/kids
What is the preferred method for diagnosis of T. gondii?
Detecting antibody in pre-suckling blood or fetal fluids
What are other methods of T. gondii diagnosis?
Antibody in post-suckle blood
Latex agglutination
IHC
Placental lesions
What placental lesions does T. gondii cause?
Focal necrosis and calcification of cotyledonary villi
How is T. gondii infection prevented?
Keep cats away from sheep feed
What Salmonella species cause salmonella abortions?
S. typhimurium, S. arizonae, S. dublin, and S. abortus-ovis (Europe)
How do ewes with Salmonella infections present?
They are sick
What lesions/CS does Salmonella cause?
Septicemia and placentitis
Dark vaginal discharge
what does Salmonella do to the fetus?
Autolyze
How is Salmonella diagnosed?
Selective media
How is Salmonella abortion treated?
Ampicillin
How is Salmonella abortion prevented?
Prevent crowding and poor sanitation
Immunization
What causes Border disease?
Pestivirus
What occurs if a ewe gets Border Disease at 0-70 days of gestation?
Fetal death, resorption, abortion, mummies
Immunotolerance - persistent infection
What occurs if a ewe gets Border Disease at 70-90 days of gestation?
Immune competence
What occurs if a ewe gets Border Disease between 90 and 147-151 (the end) days of gestation?
Congenital anomalies and weak lambs closer to the 90 mark normal lambs (later on)
What clinical signs are associated with Border Disease?
Barren ewes or ewes that give birth to weak and hairy lambs
What lesions does Border Disease cause in fetuses?
Cerebellar hypoplasia, hydrocephalus, and microgyra
How is Border disease diagnosed?
Histopath on aborted fetuses
FA and virus isolation
Serum neutralization
How is Border disease prevented/controlled?
Do not mix pregnant sheep and goats with cattle
+/- Exposure of replacement ewes before breeding
Is there a vaccination for Border Disease?
No
What does mucosal disease in PI border disease lambs cause?
Persistent diarrhea
Death in 3-14 days
What does Brucella ovis cause?
Ram epididymitis
Late-term abortion, stillbirths, and weak lambs
Necrotic and suppurative placentitis
How is Brucella ovis transmitted?
Venereally from ewes to rams
How is Brucella ovis infection diagnosed?
Serology or culture
T/F: Brucella ovis immunized rams are serologically positive.
True
Is B. mellitensis a problem for sheep or goats?
goats
Is Leptospiral abortion a problem in sheep or goats?
goats
What are the most common Leptospira serovars that cause abortions in goats?
Grippotyphosa and pomona
When does leptospiral abortion occur?
At the time of leptospiremia
What clinical disease does leptospira cause?
Icterus, hemoglobinuria, anemia, and fever
How is Leptospira infection diagnoseD?
Serology and histopath
T/F: Immunization for Leptospira is recommended for goats
True
What are the two phases of Coxiella burnetii infection?
Phase I - highly infectious and the most commonly isolated
Phase II - Antigenically distinct and less infectious
How is Coxiella burnetii spread?
Via the respiratory route among ruminants
Discharge from reproductive tract
Milk and urine
Is Coxiella burnetii infection more common in sheep or goats?
goats
How do Coxiella abortions present?
There are occasional outbreaks of weak lambs/kids and abortions
What does Coxiella do to the placenta?
Copious gray-brown exudate covering the placenta and inflammation of the intercotyledonary areas
How is Coxiella abortion diagnosed?
Lesions
Gimenez- FA- or IHC- stained organisms
PCR on placental tissue
Q-Fever antibody test kit
Is there a vaccine for Coxiella?
Yes, but only in Europe
What causes arthrogryposis-hydranencephaly in small ruminants?
Infection in early gestation with Cache Valley Fever Virus
What is Cache Valley Fever Virus transmitted by?
Mosquitos
What lesions does Cache Valley Fever Virus cause?
Congenital AGH, poor muscle development, abortion, dystocia, weak lambs, and kids
Back may be twisted or bent
Jaw shortened
How is arthrogryposis/hydranencephaly prevented?
Avoid breeding during the mosquito season
T/F: Spider lambs are caused by a virus.
False - they are a result of a genetic defect, not due to a virus
What does caprine herpesvirus 1 cause?
Abortions with a fresh or autolyzed fetus
Necrosis and intranuclear inclusions in the liver, lungs etc
How is CHV-1 diagnosed?
VI, PCR, or IHC
What are some general practices for prevention of abortion in small ruminants?
Immunize: Campy, Chlamydia, and others if available
Do not feed ewes on the ground
Prevent contamination of feed
Neuter cats and maintain a stable population
Feeding CTC (chlortetracycline) the last 6 weeks of gestation
House first lambing ewes and replacement ewes separately
Do not mix groups of pregnant ewes
Do not bed pregnant ewes with bedding from lambing areas
Avoid stresses and crowding