Other names


Causal Agent

Virus.  A very small DNA non enveloped virus which makes it very resistant to disinfectants and the environment.  Pig Parvovirus is different from other parvoviruses affecting dogs and cats.

Parvovirus particles

Parvovirus particles in the electron-microscope

Age group

Only fetuses.  To calculate the age of the foetus use the crown to rump length in cm = x.  The age of the foetus is equal to 21.07 + 0.311x.  

More simply this can be remembered as:  (Crown-rump in mm/3)+21 = days

Clinical signs

Piglets growers adults

None.   Parvovirus has a possible role in the post-weaning wasting syndrome.



Repro gilts coming into heat


Parvovirus mummified piglet


PRRS stillborn


The effects depend on the age of the foetus resulting in death or weakness

Age foetus infected

Effect on the foetus

10-30 days of age

Death and reabsorption – mother returns to oestrus

30-70 days of age

Death and mummification

Bone develops after 35 days therefore reabsorption cannot occur

70 - term

Birth of weak piglets and mummification.

After day 70 the piglet is able to mount a weak immune response to fight the disease itself

The disease is able to move across the placenta and then to each foetus along the uterus.  Therefore, the foetuses die at various ages/stages of pregnancy, and therefore have a variety of crown-rump lengths.

In the sow the clinical picture is stillbirths, mummified piglets, embryonic deaths, infertility, and the production of a significantly reduced born alive.

Parvovirus is an unlikely diagnosis when the born alive is over 8.

Abortion is not a feature of Parvovirus infections


Serology and virus isolation


The disease can be transmitted 30 km by air.  The disease can be transmitted via semen

Buildings remain infective for 4 months



None to the infected animals


Note maternal antibodies are persistent to 6 months of age.  Therefore, vaccination must be delayed in breeding gilts until over 6 months of age.  In normal instances there is no requirement for second vaccination as the field strain will ‘vaccinate’ the gilt.  Field immunity is probably life long.  Check field strain presence by serology

As an alternative to routine vaccination, some farms will blood test every 3 months a batch of gilts over 6 months of age.  If serological evidence of circulating farm parvovirus exists and feed back/introduction programmes are good, there is no requirement to vaccinate

Feedback and introduction programmes

It is essential to ensure that all new breeding stock are properly introduced onto the farm.  Weaner faeces are a good source of parvovirus particles


Mycotoxins, Enterovirus.  Other reproductive problems