FOP 3 Bovine notes + presentation Flashcards
when does abortion occur after infection with Pestivirus A/B (BVDV)? what lesions can will we see?
Abortion occurs 10 to 27 days after infection, but there may be no macroscopic or histological lesions, and virus isolation is not always successful.
how can we identify the cause of abortion as caused by organisms vs contaminants? what should we observe?
Examination of the placenta is focused on identifying lesions caused by infectious agents.
Basic observations should include
* freshness
* placental and fetal weight
* distribution of lesions, both within each membrane
and between membranes
how much should the placenta weigh compared to the bovine fetus?
Placental weight is usually about 14% of fetal weight.
Placental insufficiency would cause this ratio to be lower.
what does the distribution of lesions in the bovine placenta tell us?
The distribution of lesions assist in determining the route of entry of the agent. The usual possibilities include ascending infection through the cervix, descending through the uterine tube, and random multifocal if hematogenous.
Ureaplasma diversum typically causes what type of lesions?
amniotic lesions
why do infecting agents have more access to the bovine amniotic fluid vs in other species?
because the amnion and chorion are fused over a part of their surface area, infecting agents have a more direct access to amniotic fluid than is the case in the horse, cat and dog.
why do infecting agents have more access to the bovine amniotic fluid vs in other species?
because the amnion and chorion are fused over a part of their surface area, infecting agents have a more direct access to amniotic fluid than is the case in the horse, cat and dog.
Abnormalities of the placenta seen in disease include:
- necrosis and infarction
- fibrin exudation
- edema
- cupping of the cotyledon
- fibrosis and thickening
- exudation onto the surface
- mineralization
- vasculitis
Fetal heart failure as a cause of abortion occurs with:
Heart failure as a cause of abortion occurs with
-BVD myocarditis (Pestivirus A/B)
-Neospora myocarditis,
-nutritional myopathy (Vitamin E / Selenium deficiency).
> note messed up liver
Fetal dermatitis is associated with
mycotic abortion
>note thickened skin, exudate, esp in neck and shoulder regions
(aspergillis fumigatus)
amnionitis is associated with
Ureaplasma abortion.
rarely: mycotic or bacterial
Focal necrosis in the liver or other fetal tissues suggests
-herpesviral infection (IBP/IPV).
-listeria
Samples collected for investigation of infectious causes of abortion should include the tissues most often affected:
bovine brain and heart especially. In addition, tissues that sample amniotic fluids are a must to collect.
proportion of cases that are infectious vs non-infectious vs unknown in bovine (by examining placenta):
No diagnosis (58%) –most likely not going to get diagnosis from sporadic cases
Non-infectious (1%)
Infectious (42%) – more important in bovine than equine!!!!
are we usually able to diagnose the reason for a sporadic failure of pregnancy in cows?
no
do bovine placentas have a good amount of reserve?
yes, much reserve
are there regional differences in FOP for bovines?
yes, marked regional differences
bovine FOP causes:
-embryonic mortality: 10%
-abortion: 1.6%
-stillbirth: 2.6%
-perinatal mortality: 4%
normal arrangement of cotyledons in bovine placenta:
4 rows in each horn
are amniotic plaques in the bovine placenta a cause for concern?
no, they are normal. Up to 1cm diameter, look just like epidermis.
what is adventitial placentation
extra placenta area just around the cotyledon
signs of placentitis in the bevine
-edema
-exudate
-necrosis of cotyledon
-thickening of intercotyledonary placenta
-cupping of cotyledon
common bacterial abortogenic agents:
what disease do they cause?
-bacillus licheniformis
-trueperella pyogenes
-Mycoplasma/Ureaplasma
>ureaplasma diversum (amnionitis, placentitis)
=>generally, cause placentitis
common fungal abortogenic agents:
what disease do they cause?
aspergillus fumigatus
>placentitis
common protozoal abortogenic agents:
what disease do they cause?
neospora caninum
>myocarditis (and rare encephalitis??) - unlikely to see lesions, though
what sort of lesions will we see from neospora caninum?
mycarditis. no lesions except in heart
what issues can protozoal abotogenic agents cause in the bovine?
encephalitis, myocarditis
common viral abortogenic agents in the bovine:
what lesions will we see?
-pestivirus A, B (BVDV): underdiagnosed; no lesions or virus isolation
-bovine alphaherpesvirus 1 (BoHV-1) > most issues caused by pregnant animals vaccinated with live virus
the original epizootic bovine abortion bacteria:
characteristics?
brucella abortus
-eradicated from canada, most of USA for the most part
-reserves in bison, deer, elk
venereal, feco-oral transmission bacteria that can cause FOP in certian regions
campylobacter fetus
bacteria spread through resp or fluids with many endospores in fetal fluids, regionally significant for FOP
coxiella burnetti
-one of the reason we consider bovine fetus/placenta as biohazardous
>likelihood you get infected is low
protozoal agent that causes FOP in natural breeding situations. Early embryonic mortality, then immunity. Regionally significant in western canada.
tritrichomonas foetus
where do we find bluetonge virus in canada
west coast, okanagan valley
-also a big deal in europe, tropics
Placentitis: stereotypical and consistent appearance:
-Most agents not very damaging – cause inflammation but not abortion
-Edema and fibrosis draw cotyledons closer together, cotyledons become thickened and cup-shaped
-Necrosis and infarction
-Fibrin exudation
-Edema
-Cupping of cotyledon
-Fibrosis and thickening of intercotyledonary placenta
-Exudation onto surface
what can cause a lacy effect on the bovine placenta, between cotyledons?
mineraliazation
lesions consistent with fetal heart failure?
liver enlarged, red, bumpy. and heart is white/pale
issue caused by ponderosa pines
pine needle abortion in cattle (california)
Pajaroeller bacter abortibovis common name and how it is spread
foothills abortions, ‘epizootic bovine abortion’
-tic borne
