BOVINE ABORTIONS Flashcards
Which agents cause early term abortion?
Tritrichomonas,BVD
Which agents cause Mid-term abortions?
Neospora
How do you test for BVD?
PCR or fluorescent antibody
How do you test for N.canium?
Titers on dam
How do you prevent IBR/BVD?
vaccination at 6 months and annual vaccination pre-breeding
You are called out to a dairy herd that has recently been experiencing reproductive problems. The dairyman reports that several cows have had late abortions (6-7 months gestation) and weak or stillborn calves in the past year and he’s never had this problem before. Several of the cows that had abortions developed placental retention and/or metritis. None of the younger pre-pubescent heifers are displaying any clinical signs. You perform a necropsy on two recently aborted fetuses and find lung consolidation in one but no other obvious abnormalities. Which of the following should you recommend?
You should be most suspicious of Brucellosis based on the assortment of signs (abortions, retained placenta, metritis and lack of signs in younger animals), the timing of abortions (last half of pregnancy), and the relatively normal appearance of the examined fetuses. Pine needle abortion typically occurs in the last trimester and abortion is characterized by a hemorrhagic condition of the placenta and fetus. Veratrum californicum is associated with the cyclops condition in sheep. Neospora causes abortion from 3-8 months gestation and typically results in an autolyzed fetus; there are usually no retained fetal membranes or metritis.
A California dairy herd has been experiencing repeat breeders, several abortions, weak calves and some congenital defects including cerebellar hypoplasia, cataracts, and thymic hypoplasia. Which of the following disease agents should you investigate as the most likely cause of these problems?
BVD virus causes all these problems, as well as persistently infected neonatal calves when the fetus is infected with the NCP biotype of BVD at 2 to 5 months gestational age.
A necropsy of an aborted bovine fetus shows enlarged lymph nodes and spleen, destructive lesions to the thymus, and evidence of chronic granulomatous infection. What is the most likely cause of this abortion?
The correct answer is epizootic bovine abortion (EBA), also called foothill abortion. This is an important disease of heifers and newly introduced cows in California foothills. The lesions are consistent with this diagnosis. The etiologic agent of EBA has yet to be identified, however we know that the vector is a tick, Ornithodoros coriaceus. T. foetus is involved with early embryonic death. Brucellosis abortions are pretty rare since it has virtually been eradicated from the U.S., but lesions include autolysis, placentitis, and bronchopneumonia. IBR causes rapid fetal death, therefore there is essentially no time for fetal response, so you are likely to see autolysis and focal necrosis of the organs.