Pigs are infected with parvovirus in the pregnant sow and abortion, stillbirth, black baby, mummy degeneration, a cause reproductive disorders such as infertility disease, sows itself does not have symptoms. Many occur in gilt and yearly occurred not related to the season, especially high incidence from August to November (mating gilt from spring to summer) are important differential diagnosis of Japanese encephalitis.

1. Agent
  Parvoviridae Parvovirus(Porcine Parvovirus, PPV)
  DNA virus, high resistant to heat and chemicals.
 
2.  Epidemiology
  The most important cause ( around 30% ) of the reproductive failure.
 
3. Clinical Signs
  Once infected by the virus causes viremia growth in this infection is built on the fetus through the placenta cause mortality. Japanese encephalitis is the differential diagnosis of the disease represents a nerve symptoms as parvovirus infection. Sows do not show any symptoms during pregnancy.

 

Infection (pregnancy) Time	Clinical Signs
Early ( < 30day)	fetus absorption ( repeat heat or conception failure)
Middle (30∼70day)	Mummy or Abortion
Late (>70day)	Weak or Normal Delivery

 
4. Prevention

1) Vaccination
   PPV vaccine ( Gilt ; 2-4 week before mating, Sow ; at weaning ).