Pseudorabies

(Aujeszky's Disease)

Pseudorabies is a viral disease that affects most warm-blooded mammals except people. Swine are it's natural hosts and outbreaks are common in many countries with extensive swine production. The disease kills numerous young piglets and causes reproductive problems in sows. Animals other than pigs, when affected with the pseudorabies virus, exhibit such signs as severe itching and self-mutilation and die quickly, leading to the name "pseudorabies". There is no vaccine or treatment.

Incidents of pseudorabies in swine producing countries are expensive. Outbreaks in the United States cost the American economy nearly $34 billion each year in lost revenue and measure to control and stamp out the diease. Canada is one of the few countries that has remained free of from pseudorabies but there is a contstant risk that it could be introduced. It occurs in many countries in Europe, Asia, Africa and North and South America. The disease has not occurred in Canada, although the United States has experienced sporadic outbreaks since 1931.

Pseudorabies can be introduced into a healthy herd of swine by:

An infected carrier animal that shows no signs of illness;
Contact between infected and susceptible pigs;
Contaminated clothing, footwear, or equipment; and
Meat products, although this is unusual.

Infected swine generally shed the virus for about 3 weeks. However a small proportion become carriers for life and shed virus periodically when under stress. As resistance increases in older animals. swine show different symptoms depending on age:

Nursing piglets may become depressed, develop high fever, refuse to drink, show nervous signs such as trembling, staggering and convulsions. Entire litters may die rapidly.
Weaner pigs show the same signs as nursing piglets except fewer die. They may also cough, sneeze, and develop conjunctivitis.
Feeders and adult pigs show the same signs, although deaths are infrequent. Sows may have reproductive problems such as abortion and stillbirths, and their entire litters may die 1-2 days after birth.

Species other than pigs die very rapidly when infected and only shed the virus for 1-2 days. Severe itching, self mutilation and rapid death are signs of pseudorabies. Animals other than swine can contract the disease by:

Contact with infected swine;
Contact with dead pigs, aborted fetuses and fetal membranes

Diagnosis is by serology indicating a previous infection, or by virus isolation.

Compiled from "Aujeszky's Disease (Pseudorabies) - Outbreak Alert" Publication 1791/E Agriculture Canada, 1988, ISBN 0 662-15821 0

Return to Foreign Animal Disease Page

References:

Surveillance: Special Issue - Exotic Diseases, Vol 23, 1996
MAF Regulatory Authority, Ministry of Agriculture
P.O. Box 2526, Wellington, New Zealand

Poultry Diseases, Fourth Edition
Jordon, F.T.W. and Pattison, M., Editors
W.B. Saunders Company Ltd., London, 1996 , ISBN 0-7020-1912-7

Notifiable Diseases: Special Issue of the State Veterinary Journal,
Vol. 5 No. 3, October 1995
Ministry of Agriculture, Fisheries and Food, United Kingdom ISSN:0269 5545

Exotic Diseases of Animals: A Field Guide for Australian Veterinarians
Geering, W.A., Forman, A.J. and Nunn, M.J.
Australian Government Publishing Service, Canberra, 1995, ISBN 0 644 33513 0

Avian Disease Manual, Third Edition
Whiteman, C.E. and Bickford, A.A.
American Association of Avian Pathologists
Kendall/Hunt Publishing Company,Dubuque, Iowa, ISBN 0-8403-5795-8

The Merck Veterinary Manual, 6th Edition, Editor: Fraser, C.M.
Merck & Co., Inc, Rahway, N.J., U.S.A., 1986, ISBN 911910-53-0

Veterinary Medicine - Eighth Edition
Radositis, O.M., Blood, D.C., and Gay, C.C.
Balliere Tindal, London, U.K., 1994, ISBN 0 7020 1592 X