Unit 4 - Female Repro 3 Flashcards
What should the normal exchange portion of the placenta look like?
fine shag carpet
What should the normal non-exchange portion of the placenta look like?
saran wrap with vessels (smooth and clear)
What does the non-exchange placenta look like in cases of placentitis?
It becomes thickened, granular, and may be covered by an exudate
What do the chorionic villi look like in cases of placentitis?
they are thickened, covered by an exudate, and cotyledons may become cupped
What are amniotic plaques and are they of pathologic significance?
they are foci of squamous epithelium on the internal surface of the amnion that are of no pathologic significance
What does placental mineralization appear as?
white streaks or mats in the amnion and allantois
Is placental mineralization of patholofic significance?
no
What is adventicious placentation?
the development of intercotyledonary placentation and accessory cotyledons due to inadequate placental exchange
What are the potential causes of adventicious placentation?
previous metritis, aggressive cleaning of retained placenta, and consequence of ongoing placentitis
What does adventicious placentation look like?
marked increase in the size of cotyledons and primitive villous placentation between the cotyledons with apparent fusion of cotyledons
What is the most common cause of abortion?
non-infecitous (2/3) - infectious is the other third
What are some non-infectious causes of abortion?
genetic, hormonal, nutritional, toxic, traumatic, metabolic, and hypoxic
What are some infectious causes of abortion?
Brucella, Leptospira, herpesvirus, Aspergillus, Neospora, and toxoplasma
What are the mechanisms of fetal infection?
via maternal blood, via open cervix, and due to chronic endometritis
What is the most common mechanism of fetal infection?
via the maternal bloodstream
How does a fetus become infected via the open cervix?
due to relaxation of the cervix during pregnancy or the organism is instilled during coitis
How does a fetus become infected when the dam has chronic endometritis?
as the fetoplacenta unit enlarges it changes the dynamics in the uterus and allows the organism to proliferate and cause abortion
What is the pathogenesis of fetal infection via the maternal bloodstream?
- The dam is infected 2. the infection enters the bloodstream 3. the agent reaches the fetus during the period of viremia/bacteremia 4. the fetus becomes infected 5. In utero death and abortion often occurs 3-6 weeks after infection of the dam
What is the pathogenesis of fetal infection via the open cervix?
- The cervix becomes relaxed 2. There is an ascending infection 3. Placentitis is initiated from the region of the cervical star 4. Abortion
What is the most important tissue to submit for abortion diagnostics?
the placenta
Whether or not a herpesvirus causes an abortion outbreak is dependent on what?
the capabilities of the agent and the level of herd/population immunity
Will a population with low or high herd immunity to herpes virus have more abortion outbreaks?
low
What is the general pathogenesis of herpes abortion?
- Infection of Dam’s upper respiratory tract and tonsil 2. Viremia 3. Placental infection 4. systemic fetal infection 5. abortion with multifocal necrotizing lesions in the fetus
What ccan cause iatrogenic infections in pregnant cows?
the use of modified live vaccines
What species does leptospira cause abortions in?
cattle, horses, pigs, and goats
What is transmission of Leptospira favored by?
close contact with infected animals, wet conditions, contamination from feral animals, access to standing water sources, access to runoff from other domestic species or wildlife
What is the pathogenesis of abortion caused by Leptospira?
- Contact with infected urine or post-calving discharge 2. Organism crosses mucous membranes or broken skin 3. Mild febrile disease associated with leptospiremia 4. fetal infection 5. Abortion (typically late gestation and 1-3 weeks following infection of the dam
What gross lesions are associated with Leptospira in horses?
swollen orange-yellow liver, perirenal edema, white radiating streaks in the kidney, and placentitis
What is the diganosis of leptospira abortion based on?
demonstration of leptospires in fetal tissues and identification of a serologic response in the dam or fetus
What is the tissue of choice for Leptospira abortion diagnosis?
kidney (and placenta in horses)
How do you test leptospirosis in the fetus?
the presence of leptospiral antibodies in the fetal thoracic fluid is indicative of in utero infection
What species is most commonly affected by mycotic abortion?
bovine (2-20%), equine (2-10%), and caprine (0.5 %)
What is the route of infection of mycotic abortion?
hametogenous or via the cervix (horse)
True or false: There are no contagious fungal causes of abortion, in any domestic species
TRUE
What is the most common fungi associated with mycotic abortions?
Aspergillus
When are fungal infections the most common?
from january through march
What is the pathogenesis of mycotic abortion?
1a. Inhalation of numerous fungal spores causing Pulmonary fungal granuloma 1b. Forestomach lesions with secondary fungal infection 2. Fungemia 3. fungus has an affinity for the fetoplacental unit 4. Placentitis interferes with fetal nutrient and gas exchanges 5. fetal death and abortion
What gross lesions are associated with mycotic abortion?
placentitis, fetal malnutrition, mycotic dermatitis, and adventitious placentation
Why does mycotic abortion cause fetal malnutrition?
decreased placental exchange
What are the preferred diagnostic samples for mycotic abortion?
PLACENTA, affected skin, and lung
Are abortions caused by bacteria contagious?
no
What are some causes of contagious bacterial abortions?
Campylobacter, brucella, leptospira, Listeria, and some species of salmonella
What are the veneral causes of bacterial abortion?
Campylobacter fetus ssp venerealis and Taylorella equigenitalis
What are some non contagious bacteria that cause abortion?
Truepurella pyogenes, E. coli, Staphylococcus, Streptococcus, Pasteurella, and Bacillus
What gross lesions are associated with bacterial abortions?
placentitis, fetal malnutrition, mycotic dermatitis, and adventitious placentation
What are the prefered specimins for bacterially caused abortions?
placenta, lung, fetal stomach contents, liver, and the kidney
