Classical Swine Fever (CSF)

In the US, Classical Swine Fever (aka Hog Cholera) is considered a foreign animal disease. Where it exists around the world, it affects only pigs and wild boars.  Characteristic signs of the disease, such as fever and bleeding under the skin, can resemble other diseases, making it important to accurately diagnose. It was first described in the US, but has since been eradicated in this country. The disease is highly contagious and can cause severe epidemics.  Biosecurity, observation and early diagnosis are important to limiting the impact of an outbreak. 

Where Is the Disease Found?

The disease is considered endemic in much of Asia, South and Central America, and parts of the Caribbean. Some countries in Europe have experienced outbreaks in the past decade. It has not been reported in Africa. Australia, New Zealand, Canada, and the United States are free of this disease.

Can the Disease Affect People?

No. Classical Swine Fever is not a public health threat.

What Are Signs of the Disease?

  • High fever
  • Lethargy
  • Weakness
  • Ataxia (incoordination)
  • Huddling
  • Anorexia (poor appetite)
  • Conjunctivitis
  • Constipation followed by diarrhea
  • Reddish/purplish discoloration of the skin of the abdomen, inner thighs and ears

The disease varies in severity. Sudden onset of severe illness can be followed by death within a week or two. With chronic forms, animals may live over a month after infection. Less severe forms may not present any classical signs of illness.  In some cases, reproductive problems and congenital abnormalities may be the only signs of the disease.

Can It Be Treated?

There is no specific treatment for Classical Swine Fever. The disease is usually fatal to pigs. Any pig with signs suggestive of Classical Swine Fever should be reported to the State Veterinarian or USDA Area Veterinarian in Charge immediately.

How Can the Disease Be Prevented?

The regulation of garbage feeding to pigs is one of the most important controls preventing the introduction or spread of Classical Swine Fever. Food scraps containing or having been in contact with meat must be boiled for 30 minutes to kill viruses and bacteria.

Vaccines may be used to control disease. This must be combined with other measures to eradicate disease. The United States, being free of the disease, does not routinely vaccinate for Classical Swine Fever.

What Causes the Disease?

Classical Swine Fever is caused by a virus in the Flaviviridae family of viruses. The disease is spread rapidly pig-to-pig through direct contact.  Movement of infected animals will spread the disease.  The disease can also be transferred from farm-to-farm by personnel, vehicles and equipment contaminated with virus-laden organic material. Bodily secretions and pork meat contain virus.  Feeding of under- or uncooked garbage containing pork meat or by-products to pigs is another route of transmission.

Where Can I Find Additional Information?