Classical swine fever remains in Japan with 15 outbreaks in 9 days

Gifu is hit hard with 14 confirmed cases of Classical swine fever in wild boar.

15 April 2019, at 11:00am

Often indistinguishable from African swine fever until pathology tests are complete, Classical swine fever (CSF) can affect any age group in a herd and mortality rates are high, making it one of the most economically-damaging pandemic viral diseases of pigs in the world. CSF affects wild boar and domestic pigs but is not a risk to humans.

Japan is the latest region to fall victim to the highly virulent disease, with its first case in 26 years emerging in September 2018. 80 pigs had died before the disease was identified and 610 pigs were subsequently slaughtered to prevent the disease from spreading. A strict disinfection procedure took place within 24 hours of culling the herd.

Since 3 April 2019, 15 outbreaks have been confirmed in cities across Gifu and Aichi. The outbreaks consisted of 17 cases in wild boar, six of which died from the disease and the remainder of the animals being killed and disposed of by authorities.

How does CSF present in pigs?

Initial signs may only present in a small group within the herd:

  • fatigue;
  • depression;
  • reluctance to move;
  • inappetence;
  • may appear constipated;
  • shivering or shaking;
  • young piglets may shiver and huddle together;
  • sudden death.

As more pigs begin to show signs of pathology and the disease progresses, more obvious signs of illness present:

  • yellow/grey diarrhoea or scours;
  • conjunctivitis of the eyes which begins as a thin discharge and progressing to a thick, adhesive discharge;
  • swollen, red eyes;
  • high fever;
  • weight loss;
  • muscle weakness and lameness;
  • partial paralysis;
  • vomiting;
  • purple colouration of skin beginning at ears and tail, followed by the snout, lower legs, belly and back;
  • abortion, embryo loss, mummification of piglets;
  • convulsions;
  • high mortality rate.

Classical swine fever is a notifiable disease. In all suspected CSF cases, laboratory tests should be done to confirm the diagnosis. Investigations are usually carried out by the authorities.

It is best to send whole dead pigs to the diagnostic laboratory so the pathologists can sample what they want. If only samples can be sent, the tonsils are best.

If you are worried about any abnormal health issues in your pig herd, try our Disease Problem Solver to check if your clinical signs match some of the hundreds of diseases we document on The Pig Site.