Swine Diseases Part I of III Julie Zimmerman Advanced Swine Production Spring 2008

Porcine Reproductive & Respiratory Syndrome (PRRS)

Advanced Swine Production What is in a name? Porcine Reproductive and Respiratory Syndrome has been called by many names, but now is referred to as PRRS Porcine Reproductive and Respiratory Syndrome has been called by many names, but now is referred to as PRRS Other names were/are: Other names were/are: Mystery Swine Disease (name first given to the disease) Mystery Swine Disease (name first given to the disease) Mystery Reproductive Syndrome Mystery Reproductive Syndrome Swine Infertility and Respiratory Syndrome (SIRS) Swine Infertility and Respiratory Syndrome (SIRS) Blue Ear Disease Blue Ear Disease Lelystad Virus (virus that causes PRRS)

Advanced Swine Production 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.

Advanced Swine Production 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

Advanced Swine Production Symptoms/Problems in Females Infertility Infertility Lethargic behavior Lethargic behavior Abortions Abortions Loss of appetite Loss of appetite Encephalitis Encephalitis Heart problems Heart problems Depression Depression Premature births Premature births Sometimes the entire litter is stillborn or very weak Sometimes the entire litter is stillborn or very weak High fever High fever

Advanced Swine Production Symptoms/Problems in Boars High fever High fever Depression Depression Infertility Infertility Primary issues with boars are the spread of disease through their semen Primary issues with boars are the spread of disease through their semen

Advanced Swine Production Symptoms/Problems in Pigs PRRS is more severe in nursery pigs than in finishing pigs. Severe pneumonia with coughing & labored breathing Severe pneumonia with coughing & labored breathing Increased pre-weaning sickness & death Increased pre-weaning sickness & death Pigs with PRRS will take longer to finish Pigs with PRRS will take longer to finish High fever High fever Depression (shows in finishing pigs) Depression (shows in finishing pigs)

Advanced Swine Production Transmission of PRRS Introduction of infected hogs into the herd Introduction of infected hogs into the herd Mucus Mucus Urine Urine Feces Feces Semen (both artificial insemination and natural) Semen (both artificial insemination and natural) Air (very unlikely) Air (very unlikely) Blood Blood

Advanced Swine Production 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. 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.

Advanced Swine Production 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).

Advanced Swine Production Prevention PRRS vaccine (not 100% effective & consideration needs to be taken due to the fact it is a modified live virus) PRRS vaccine (not 100% effective & consideration needs to be taken due to the fact it is a modified live virus) Clean farrowing houses Clean farrowing houses Disinfection & drying of pens Disinfection & drying of pens Better management practices Better management practices Quarantine incoming hogs for 60 days Quarantine incoming hogs for 60 days Realize facility’s limitations and do not overcrowd Realize facility’s limitations and do not overcrowd Prevent infected stock from entering herd Prevent infected stock from entering herd Do “homework” on potential purchases, investigate the herd, herdsman and general management practices before committing to buy. Do “homework” on potential purchases, investigate the herd, herdsman and general management practices before committing to buy.

Advanced Swine Production Sources 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 Epperson, B., D. Benfield, K. Rossow. “Porcine Reproductive and Respiratory Syndrome (PRRS)”. SDSU Extension Fact Sheets. Harper, A. “An Overview of Porcine Reproductive and Respiratory Syndrome”. Livestock Update. July Lawhorn, B. “Porcine Reproductive and Respiratory Syndrome”. Texas AgriLife Extension Service Educational Materials.

Advanced Swine Production Sources, Continued Norby, M. “Vet scientist leading the way in fight against devastating viral swine disease”. Research Nebraska. Sept Plagemann, P. “Porcine reproductive and respiratory syndrome virus: origin hypothesis”. Emerging Infectious Diseases. Aug South Dakota State University, Veterinary Science Department. “Porcine Reproductive and Respiratory Syndrome (PRRS)” Van Alstine, G., G. Stevenson, C. Kanitz. “Diagnosis of Porcine Reproductive and Respiratory Syndrome”. Animal Disease Diagnostic Laboratory. Newsletter

THE END