Multifocal hepatic necrosis in a bovine fetus

History:  Two aborted bovine fetuses were submitted.  One had been partially scavenged, the other was intact.   The herd was vaccinated on 10/10/08 with Bovishield Gold VL5 and Ultrabac 7.   There are 24 heifers in the herd and 6 have aborted at the same time.

Gross Lesions: None, the placenta was not submitted

Histopathology:

Most tissues were autolyzed severely.  One fetus had no lesions, the other had the following:

 

Liver: There are multifocal random areas of hepatocellular necrosis surrounded by intact hepatic parenchyma. The necrotic areas are characterized by loss of hepatic cord and sinusoidal architecture with cellular and karyorrhectic debris with no associated inflammation.

Lungs: There are small fragments of meconium in multifocal alveoli scattered throughout the lung.

 

Liver- Multifocal areas of necrosis at low power

 

Liver- Necrosis at high power

 

 

 

Lab Tests:  

Aerobic culture (Lung, liver, stomach contents): Streptococcus zooepidemicus, Aeromonas sp, Streptococcus sp (Alpha hemolytic), and Staphylococcus sp (Non-hemolytic).

Comment:

Multifocal hepatic necrosis is commonly caused by IBR (BHV-1).  Virus isolation and FA tests were both negative for IBR.  Once the culture results came back we called this a bacterial septicemia.  Because of the autolysis we can’t tell for sure if some of the cellular and nuclear debris is from hepatocytes or leukocytes.  This appears to be a case of sporadic bacterial abortion.  The other fetus was pretty much useless for diagnosis.  The presence of meconium in the lungs is generally attributed to fetal distress (hypoxia)  in utero resulting in release of meconium and aspiration of amniotic fluid with meconium.