Transcript Swine Diseases - Tarleton State University

Swine Diseases
Part I of III
Julie Zimmerman
Advanced Swine Production
Spring 2008
Porcine Reproductive
&
Respiratory Syndrome
(PRRS)
What is in a name?
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Porcine Reproductive and Respiratory Syndrome
has been called by many names, but now is
referred to as PRRS
Other names were/are:
Mystery Swine Disease (name first given to the
disease)
 Mystery Reproductive Syndrome
 Swine Infertility and Respiratory Syndrome (SIRS)
 Blue Ear Disease
 Lelystad Virus (virus that causes PRRS)
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What is PRRS?
PRRS was discovered in 1987 in the United States
and 1991 in the Netherlands, soon spreading
throughout all of Canada and Europe.
There are so many different strains of PRRS that
preventative vaccines are not 100% effective.
PRRS is a virus that causes reproductive failure in
breeding stock and respiratory tract failure in
young pigs.
PRRS costs the United States swine industry
approximately $600 million yearly.
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Origination
Researchers at the University of Minnesota
hypothesized that:
“A mutant of a closely related arterivirus of mice (lactate
dehydrogenase-elevating virus) infected wild boars in central Europe.
These wild boars functioned as intermediate hosts and spread the
virus to North Carolina in imported, infected European wild boars
in 1912; the virus then evolved independently on the two continents
in the prevalent wild hog populations for approximately 70
years until independently entering the domestic pig population.”
- Peter G.W. Plagemann
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Symptoms/Problems in Females
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Infertility
Lethargic behavior
Abortions
Loss of appetite
Encephalitis
Heart problems
Depression
Premature births
Sometimes the entire litter is stillborn or very weak
High fever
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Symptoms/Problems in Boars
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High fever
Depression
Infertility
Primary issues with boars are the spread of
disease through their semen
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Symptoms/Problems in Pigs
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PRRS is more severe in nursery pigs
than in finishing pigs.
Severe pneumonia with coughing & labored
breathing
Increased pre-weaning sickness & death
Pigs with PRRS will take longer to finish
High fever
Depression (shows in finishing pigs)
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Transmission of PRRS
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Introduction of infected hogs into the herd
Mucus
Urine
Feces
Semen (both artificial insemination and natural)
Air (very unlikely)
Blood
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Many hogs die from secondary
infection, due to the fact there is no
vaccine for post infected animals. For
this reason, vaccination is important to
treat that secondary infection, once
PRRS has been diagnosed.
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A common misconception about
PRRS is that if the hog acquires
the virus and lives, it will then be
immune for the rest of its life.
This is not true, not only can the hog
acquire the disease again, but could also
recover and live out its
days
as carrier (showing no signs).
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Prevention
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PRRS vaccine (not 100% effective & consideration
needs to be taken due to the fact it is a modified live
virus)
Clean farrowing houses
Disinfection & drying of pens
Better management practices
Quarantine incoming hogs for 60 days
Realize facility’s limitations and do not overcrowd
Prevent infected stock from entering herd
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Do “homework” on potential purchases, investigate the herd,
herdsman and general management practices before
committing to buy.
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Sources
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Benfield, D., J. Hennings, J. Collins, S. Dee, W. Mengeling, K. Rossow, J.
Zimmerman. “Porcine Reproductive and Respiratory Syndrome (PRRS)”. Pork
Industry Handbook. Nov. 2002: 1-8.
Dee, S. “Porcine Reproductive and Respiratory Syndrome”. The Merck Veterinary
Manual. 2006.
 http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/54100.htm
Epperson, B., D. Benfield, K. Rossow. “Porcine Reproductive and Respiratory
Syndrome (PRRS)”. SDSU Extension Fact Sheets.
 http://vetsci.sdstate.edu/xnews/eeprrs.html
Harper, A. “An Overview of Porcine Reproductive and Respiratory Syndrome”.
Livestock Update. July 1996.
 http://www.ext.vt.edu/news/periodicals/livestock/aps-96_07/aps-665.html
Lawhorn, B. “Porcine Reproductive and Respiratory Syndrome”. Texas AgriLife
Extension Service Educational Materials.
 http://animalscience.tamu.edu/main/academics/swine/L5137-prs.pdf
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Sources, Continued
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Norby, M. “Vet scientist leading the way in fight against devastating viral
swine disease”. Research Nebraska. Sept. 1998.
 http://ard.unl.edu/rn/0998/prrs.html
Plagemann, P. “Porcine reproductive and respiratory syndrome virus: origin
hypothesis”. Emerging Infectious Diseases. Aug. 2003.
 http://www.cdc.gov/ncidod/EID/vol9no8/03-0232.htm
South Dakota State University, Veterinary Science Department. “Porcine
Reproductive and Respiratory Syndrome (PRRS)”. 2003.
Van Alstine, G., G. Stevenson, C. Kanitz. “Diagnosis of Porcine Reproductive
and Respiratory Syndrome”. Animal Disease Diagnostic Laboratory. Newsletter
1993.
 http://www.addl.purdue.edu/newsletters/1992-93/prrs.shtml
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THE END