Background and history

There are two viruses, which are in the same group of pestiviruses as the virus of swine fever (hog cholera) but which primarily infect cattle and sheep respectively, can get into pig breeding herds and cause reproductive problems. These include poor conception rates, a few abortions, foetal death, mummification, small litters and low birth weights. They rarely cause any other clinical signs in pigs. This disease is not a common cause of infertility in the sow and would be considered low on the list of priorities from a diagnostic point of view.

Clinical signs

Piglets, weaners and growers

• N/A

Sows

• Poor conception rates.
• A few abortions.
• Foetal death.
• Mummification.
• Small litters.
• Low birth weights.

Diagnosis

Laboratory tests. Serology and isolation.

Causes

Transmission to pigs usually requires direct contact with cattle or sheep. Other possible methods by which infection may be introduced into the herd include exposure of pigs to cattle or sheep faeces, feeding of un-pasteurised cow's milk, or in contaminated live-attenuated virus vaccines.

• Exposure of pigs to cattle or sheep faeces.
• Feeding of un-pasteurised cow's milk.
• Contaminated live-attenuated virus vaccines.

A problem may arise in regions in which swine fever is endemic and in which routine screening of herds for swine fever is carried out. Pigs which have been infected with BVDV or BDV are positive to the common tests. Specialised tests have to be done to differentiate them which takes time while a standstill is enforced.

Prevention

Prevent exposure to the pathogens.

Treatment

There is no treatment and the infections are self eliminating.