Welcome to Circle H Animal Health

Dr. William (Bill) R. DuBois, DVM, ABVP, is from eastern Oklahoma where his family has a commercial cow-calf operation. He graduated from Oklahoma State University with a Bachelor of Arts degree in Spanish in 1992 and Doctor of Veterinary Medicine in 1996. After graduation, he joined Oliphant Veterinary Clinic in Offerle , KS , as an associate veterinarian. He then worked as an associate veterinarian at Veterinary Medical Associates in Cushing , OK .

He completed a Food Animal Medicine and Surgery Residency at Oklahoma State University in 2000. After completion of the residency, he joined the faculty in the Department of Large Animal Clinical Sciences at the University of Tennessee as an assistant professor teaching food animal medicine and surgery.

Dr. DuBois joined Veterinary Research and Consulting Services in Greeley , CO in 2003. As an Associate Veterinarian, Dr. DuBois was involved in beef feedlot consultation and contract research. While with VRCS, he worked as part of a team to develop, implement, and monitor animal health programs for over 2 million cattle received per year. One of the primary focuses of the practice was to train and work closely with animal health personnel.

In January of 2006, Dr. DuBois joined Circle H Animal Health. He will team with Dr. Scanlon Daniels to provide consultation services for swine clients, as well as continue contract research.

Dr. DuBois currently resides in Mustang, OK with his wife Angela, daughter Iris and son Vince. Dr. DuBois' current professional interests are food animal health, food systems production management and food animal research. His involvement in professional associations and publications & presentations are listed below.

Oklahoma Veterinary Medical Association (2000-2002)

PUBLICATIONS & PRESENTATIONS

Rogers KC, DuBois WR, Portillo TA, Miles DG. Effects of two dosage levels of doramectin on health,growth performance and carcass characteristics in finishing beef steers. The Bovine Practitioner 38(2): 171-176 ,2004.

DuBois WR, Prado TM, Ko JCH, Mandsager RE, Morgan GL. A comparison of two intramuscular doses of xylazine-ketamine combination and tolazoline reversal in llamas. Veterinary Anaesthesia and Analgesia 31(2): 90-96, 2004.

Kirkpatrick JG, Fulton RW, Burge LJ, DuBois WR, Payton M. Passively transferred immunity in newborn calves, rate of antibody decay, and effect on subsequent vaccination with modified live virus vaccine. The Bovine Practitioner 35(1): 47-55, 2001.

DuBois WR, Cooper VL, Duffy JC, Dean DD, Ball RL, Starr BD. A preliminary evaluation of the effect of vaccination with modified live bovine viral diarrhea virus (BVDV) on detection of BVDV antigen in skin biopsies using immunohistochemical methods. The Bovine Practitioner 34(2): 98-100, 2000.

DuBois WR. Bovine vaccinology for beef cattle producers. Proceedings UT Beef and Forage Field Day. 2002.

DuBois WR. Urolithiasis in small ruminants. Proceedings of the North American Veterinary Conference. 2002.

DuBois WR. Injectable anesthesia in llamas and alpacas. Proceedings of the North American Veterinary Conference. 2002

Daugherty R, DuBois WR, Hopkins F, Welborn M. Health Management of Beef Cattle, in Tennessee Master Beef Producer Manual. Agriculture Extension Service, University of Tennessee . p 8-1 to 8-27.)

DuBois, WR. Bovine viral diarrhea virus: an update. Tennessee Veterinary Medical Association Tennessee Cattlemen's Association Veterinary Continuing Education Meeting. Frankin, TN. October 2001.

DuBois, WR. An introduction to standardized performance analysis in beef herds. Tennessee Veterinary Medical Association Tennessee Cattleman's Association Veterinary Continuing Education Meeting. Frankin, TN. October 2001.

DuBois WR. On farm biosecurity measures for the cow-calf producer. Tennessee Cattleman's Association Annual Convention. Franklin , TN. October 2001.

Ryan L. Royer DVM Dr. Ryan L. Royer was born and raised in Clinton, Iowa on a small beef cow-calf operation. He attended Iowa State University and received his Bachelor’s of Science degree in Animal Science in 1998, and continued at Iowa State University receiving his doctor of veterinary medicine degree in 2002. During his undergraduate studies and into veterinary school, Dr. Royer was extensively involved in swine research projects involving PRRS, SIV, M.hyo and circovirus.

Upon completion of his veterinary degree, Ryan became an associate with the Cresco Veterinary Clinic in Cresco, IA, practicing traditional mixed animal medicine. In 2003, he moved to Elkader, another town in northeast Iowa, where he became a partner of the Elkader Veterinary Clinic, LLC. Dr. Royer’s primary focus was dairy and swine production medicine. During his time with the Elkader Veterinary Clinic, Dr. Royer was involved with several Johne’s research projects in collaboration with researchers at Iowa State University.

Ryan and his wife, Jennifer, live in Dalhart with their 3 children, Daniel, Lizzie, and Katie.

Dr. Royer’s current area’s of interest are dairy herd health programs, swine herd health programs, and food animal research. His professional memberships and publications and presentations are listed below.

PROFESSIONAL ORGANIZATIONS:

American Veterinary Medical Association (2002 – present) Iowa Veterinary Medical Association (2002 – present) American Association of Swine Veterinarians (2002 – present) American Association of Bovine Practitioners (2002 - present)

Professional Publications and Presentations:

Ratree Platt, DVM, PhD; James A. Roth, DVM, PhD, Ryan L. Royer, DVM, Charles O. Thoen, DVM, PhD. Monitoring responses by use of 5-color flow cytometrty in subsets of peripheral T cells obtained from cattle inoculated with a killed Mycobacterium avium subsp paratuberculosis vaccine. AJVR, Vol 67, No. 12, December 2006.

Fenaux M, Halbur PG, Haqshenas G, Royer R, Thomas P, Nawagitgul P, Gill M, Toth TE, Meng X-J. Cloned genomic DNA of type 2 porcine circovirus is infectious when injected directly into the liver and lymph nodes of pigs: Characterization of clinical disease, virus distribution, and pathologic lesions. J or Virol 76(2):541-551, 2002.

Royer RL, Nawagitgul P, Halbur PG, Paul PS. Susceptibility of porcine circovirus type 2 to commercial and laboratory disinfectants. Journal of Swine Health and Production 9(6):281-284, 2001.

Thanawongnuwech R, Brown GB, Halbur PG, Roth JA, Royer RL, Thacker BJ: Pathogenesis of porcine reproductive and respiratory syndrome virus-induced increase in susceptibility to Streptococcus suis infection. Veterinary Pathology 37:143-152, 2000.

XJ Meng, PG Halbur, JS Haynes, TA Tsareva, JD Bruna, RL Royer, RH Purcell, SU Emerson. Experimental infection of pigs with the newly identified swine hepatitis E virus, but not with human strains of HEV. Archives of Virology 143: 1405-1415, 1998.

Thanawongnuwech R, Halbur PG, Ackerman MR, Thacker EL , Royer RL: Effects of low (modified – live virus vaccine) and high (VR-2385) virulence strains of porcinereproductive and respiratory syndrome virus (PRRSV) on pulmonary clearance of copper particles in pigs. Veterinary Pathology 35: 398-406,1998.

Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. In Proceedings of the Collaboration between College of Veterinary Medicine, ISU and Faculty of Veterinary Science, Chulalongkorn University, August 1-8, 2001,pp41-44.

Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. In Proceedings of American Association of Swine Practitioners 31.45

Halbur PG, Sorden SD, Royer RL, Bruna J: Investigation into the severe acute PRRS outbreaks.1997 Iowa State University Swine Research Reports, pp150-151.

Thanawongnuwech R, Halbur PG, Royer RL, Bruna J: PRRS virus-induced damage to intravascular macrophages. 1997 Iowa State University Swine Research Reports, pp 152-153.

HF Rotto, PG Halbur, PS Paul, SS Schuchaskie, RL Royer. Effects of Different Strains of Porcine Reproductive and Respiratory Syndrome Virus on Lymph Node Morphology. In Proceedings of American Association of Veterinary Laboratory Diagnosticians, p30, October, 1997.

Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. Presented at the Spring Conference of the Iowa Veterinary Medical Association, 2000, Ames, IA.

Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. Presented at the Collaboration between College of Veterinary Medicine, ISU and Faculty of Veterinary Science, Chulalongkorn University, 2001, Bangkok, Thailand.

NorthEast Iowa Dairy Days – 2004. Proper Foot Health – Maintenance and Pathology.

Clayton & Fayette County Land-O-Lakes/Purina Feeds Barn Meeting – 2007. Observations in the Transition Pen from a Practicing Veterinarian.


Jump To: Dr. Scanlon Daniels Dr. Angela Daniels Dr. Bill DuBois Dr. Ryan Royer		Dr. Scanlon Daniels Dr. C. Scanlon Daniels, DVM MBA was born in central Iowa where his family operated a farrow-to-finish swine operation and a cow calf herd. He graduated from Iowa State University with a Bachelor of Science degree in Animal Science in 1997 and Doctor of Veterinary Medicine in 1998. In 2003, he graduated from the University of Guelph with a Master of Business Administration degree. After graduation from veterinary school, Dr. Daniels accepted a production veterinarian position with Iowa Select Farms in Iowa Falls, IA where he was responsible for maintaining regulatory compliance, monitoring system health and implementing health improvement processes in a 96,000 sow integrated live hog production system. In 1999, he accepted a veterinarian position with Seaboard Farms, Inc. During five years at Seaboard Farms in Guymon, OK, he led their Health Assurance Team consisting of seven veterinary, technical and administrative staff. That team was responsible for managing live production health for the third largest pork production company in the US. He was directly responsible for developing the animal health products budget and was a critical member of live production management team and integrated research and development group. During his time there, Dr. Daniels gained extensive experience from numerous PRRSV and Mycoplasma elimination projects. In April of 2004, Dr. Daniels joined Dr. Angela Daniels in the recently-founded Circle H Animal Health, LLC food animal veterinary practice in Dalhart, TX. Dr. Daniels currently resides in Dalhart, Texas with his wife Angela, and sons Eric, Luke and Judd. Dr. Daniels current professional interests are food animal health, food systems production management and food animal research. His involvement in professional associations and publications & presentations are listed below. PROFESSIONAL ASSOCIATIONS American Association of Swine Veterinarians (1994 to Present) American Veterinary Medical Association (1994 to Present) American Association of Industrial Veterinarians (2001 to Present) American Association of Veterinary Laboratory Diagnosticians (2003 to Present) Advisory Board Member, Center for Swine Disease Eradication (2000 to 2004) National Pork Board Veterinary Advisory Group (2003 to Present) High Plains Dairy Council (2004 to Present) Dalhart Chamber of Commerce (2004 to Present) Academy of Veterinary Consultants (2004 to Present) PUBLICATIONS & PRESENTATIONS Daniels, C.S., Cowan, T.S. and Sornsen, S.A. 1997. Clinical field study to identify swine respiratory pathogens present in grow-finish pigs and assess their impact on performance. American Association of Swine Practitioners Proceedings, 237-238. Daniels, C.S., Hoffman, L.J., Apley, M.D., and Schwartz, K.J., 1998. Antimicrobial susceptibility profiles of swine pathogens tested at the Iowa State University Veterinary Diagnostic Laboratory. American Association of Swine Practitioners Proceedings, 59-60. Daniels, C.S., Daniels, A.M., and Karriker, L. 2003. Challenges in diagnosis and control of swine influenza virus. American Association of Swine Veterinarians Proceedings. 381-386. Daniels, C.S., Thacker, B., Sornsen, S., and Thacker, E. 1999. Survey of Mycoplasma hyopneumoniae maternally-derived antibodies in suckling pigs. Allen D. Leman Swine Conference Recent Research Reports, 41. Fitzsimmons, M.A. and Daniels, C.S. 2003. Control in large systems. 2003 PRRS Compendium, 137-142. J. Zimmerman, K.-J. Yoon (eds). National Pork Board, Des Moines, Iowa. Daniels, C.S. and Fitzsimmons, M.A. 2002. PRRS control in large systems. Trends in Emerging Viral Infections of Swine, A. Morilla, K.-J. Yoon, J. Zimmerman (eds). Iowa State University Press, Ames, Iowa. Daniels, C. S. 2003. Area spread of PRRSV from a small population of backyard pigs. American Association of Swine Veterinarians pre-conference session, Preventing and controlling PRRSV: mission impossible? Daniels, C.S. 2003. PRRS control on large farms. The North American Veterinary Conference, 2003 Proceedings, 320. Daniels, C.S. 2003. Prioritizing time and vet services. The North American Veterinary Conference, 2003 Proceedings, 321. Daniels, C.S. 2003. Active monitoring of a systems health status. The North American Veterinary Conference, 2003 Proceedings, 318-319. Daniels, C.S. 2003. The economics of depopulation & repopulation versus herd closure for control of porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae in a multi-site swine production system. Masters project, University of Guelph, Ontario. Daniels, C.S. 2001. Group-based sow record keeping. American Association of Swine Veterinarians Pre-conference Session: Making your life easier with computer information services.
		Dr. Angela Daniels Dr. Angela M. Daniels was born in Southeast Iowa and was raised on a diversified farm where her family raised beef cattle, hogs, corn and soybeans. She graduated from Iowa State University with Bachelor of Science degrees in Dairy and Animal Science in 1995. She then entered the College of Veterinary Medicine at Iowa State University and received a Doctor of Veterinary Medicine in 1999. After graduation, Dr. Daniels accepted a position with Dr. C.J. Johanns in his Dairy Production Medicine business. Their clients were spread across the state of Iowa and their services centered on reproduction and record analysis. After a job transfer moved their family to the Oklahoma and Texas Panhandle region, she worked with Dr. Dan Kullot in Syracuse, KS as well as the Dalhart Animal Hospital before accepting a Staff Veterinarian position with Seaboard Farms, Inc. During her three years at Seaboard Farms, she was responsible for health of one segment of some 48,000 sows and their down flow production. An area of interest for Dr. Daniels was food safety and she worked on projects involving needle-free injections and Trichinae certification to promote food safety for the company. In 2002, she rejoined the Dalhart Animal Hospital to focus on dairy production medicine for new producers in the Dalhart region. In January of 2004, she and Dr. C. Scanlon Daniels founded Circle H Animal Health, LLC where she continued her work in the dairy field. Dr. Daniels lives in Dalhart, TX with her husband Scanlon and sons Eric, Luke and Judd. Her professional interests are in the areas of milk quality, replacement heifer production, food safety, and livestock research. Her involvement in professional organizations and publications is outlined below. PROFESSIONAL ORGANIZATIONS American Association of Bovine Practitioners (1995 to Present) American Veterinary Medical Association (1995 to Present) American Association of Swine Veterinarians (1995 to Present) NMC, a Global Milk Quality Organization (2000 to Present) AABP Mastitis Committee (2003 to Present) Academy for Veterinary Consultants (2002 to Present) High Plains Dairy Council (2004 to Present) Dalhart Area Chamber of Commerce (2004 to Present) Professional Dairy Heifer Growers Association (2005 to Present) Academy for Rural Veterinarians (2005 to Present) PUBLICATIONS & PRESENTATIONS Menke, A. L. 1994. Evaluation of activity monitors for detection of estrus in dairy cattle. J. Dairy Sci. 72:393. Menke, A. L. and C. R. Youngs. 1995. Iowa Cattlemen's Association 1994-1995 Bull Evaluation Program Project. Iowa Cattlemen's Association Bull Evaluation Program 1994-1995 Annual Summary. Section 7, pp 5-14. R. F. Rosenbusch, A. M. Daniels, E. L. Carney, T. H. Smith. 1996. Incidence of colostrums infected with Mycoplasma bovis among Iowa dairy herds and impact on respiratory tract infection in calves. Iowa State University Dairy Report DSL-105. Halbur, P. G., A. M. Daniels and R. F. Rosenbusch. 1997. Morphologic changes and tissue dissemination following intrathoracic or subcutaneous innoculation of Mycoplasma bovis in neonatal Holstein calves. Presented at the ISU Merck's Scholar Awards. Daniels, C.S., Daniels, A.M., and Karriker, L. 2003. Challenges in diagnosis and control of swine influenza virus. American Association of Swine Veterinarians Proceedings 381-386. Bovine Veterinarian, Sept 2004, "Tools of the Trade", pp 32-34, 36, "Consider Visual Treatment Protocols" p 14. Southwest Dairyman, vol 4 no 2, "New Milk Quality and Livestock Diagnostic Disease Lab Opens in Amarillo", p 8. Dairy Herd Management, Feb 2005, Dairy Veterinary Trends 2004 insert, "Vaccine Protocols That Sing", p6. Bovine Veterinarian, Sept 2005, "Creating New Haul-in Facilities", pp 70-72, 74. Feedstuffs, Dec 12, 2005, vol 77 no 51, "Cheese Plant Sparks Dairy Boom", p 20. Dairy Herd Management, March 2007, "Listen to Your Cows" , p 82. Dairy Herd Management, June 2007, "Choose the Right Mastitis Tube", p 66.

		Dr. Bill DuBois Dr. William (Bill) R. DuBois, DVM, ABVP, is from eastern Oklahoma where his family has a commercial cow-calf operation. He graduated from Oklahoma State University with a Bachelor of Arts degree in Spanish in 1992 and Doctor of Veterinary Medicine in 1996. After graduation, he joined Oliphant Veterinary Clinic in Offerle , KS , as an associate veterinarian. He then worked as an associate veterinarian at Veterinary Medical Associates in Cushing , OK . He completed a Food Animal Medicine and Surgery Residency at Oklahoma State University in 2000. After completion of the residency, he joined the faculty in the Department of Large Animal Clinical Sciences at the University of Tennessee as an assistant professor teaching food animal medicine and surgery. Dr. DuBois joined Veterinary Research and Consulting Services in Greeley , CO in 2003. As an Associate Veterinarian, Dr. DuBois was involved in beef feedlot consultation and contract research. While with VRCS, he worked as part of a team to develop, implement, and monitor animal health programs for over 2 million cattle received per year. One of the primary focuses of the practice was to train and work closely with animal health personnel. In January of 2006, Dr. DuBois joined Circle H Animal Health. He will team with Dr. Scanlon Daniels to provide consultation services for swine clients, as well as continue contract research. Dr. DuBois currently resides in Mustang, OK with his wife Angela, daughter Iris and son Vince. Dr. DuBois' current professional interests are food animal health, food systems production management and food animal research. His involvement in professional associations and publications & presentations are listed below. PROFESSIONAL ORGANIZATIONS Diplomat of the American Board of Veterinary Practitioners Food Animal Specialty (2001-Present) American Veterinary Medical Association (1996-Present) American Association of Bovine Practitioners (1999-Present) American Association of Swine Veterinarians (1999-Present) Academy of Veterinary Consultants (2002-Present) Tennessee Veterinary Medical Association (2000-2002) Oklahoma Veterinary Medical Association (2000-2002) PUBLICATIONS & PRESENTATIONS Rogers KC, DuBois WR, Portillo TA, Miles DG. Effects of two dosage levels of doramectin on health,growth performance and carcass characteristics in finishing beef steers. The Bovine Practitioner 38(2): 171-176 ,2004. DuBois WR, Prado TM, Ko JCH, Mandsager RE, Morgan GL. A comparison of two intramuscular doses of xylazine-ketamine combination and tolazoline reversal in llamas. Veterinary Anaesthesia and Analgesia 31(2): 90-96, 2004. Kirkpatrick JG, Fulton RW, Burge LJ, DuBois WR, Payton M. Passively transferred immunity in newborn calves, rate of antibody decay, and effect on subsequent vaccination with modified live virus vaccine. The Bovine Practitioner 35(1): 47-55, 2001. DuBois WR, Cooper VL, Duffy JC, Dean DD, Ball RL, Starr BD. A preliminary evaluation of the effect of vaccination with modified live bovine viral diarrhea virus (BVDV) on detection of BVDV antigen in skin biopsies using immunohistochemical methods. The Bovine Practitioner 34(2): 98-100, 2000. DuBois WR. Bovine vaccinology for beef cattle producers. Proceedings UT Beef and Forage Field Day. 2002. DuBois WR. Urolithiasis in small ruminants. Proceedings of the North American Veterinary Conference. 2002. DuBois WR. Injectable anesthesia in llamas and alpacas. Proceedings of the North American Veterinary Conference. 2002 Daugherty R, DuBois WR, Hopkins F, Welborn M. Health Management of Beef Cattle, in Tennessee Master Beef Producer Manual. Agriculture Extension Service, University of Tennessee . p 8-1 to 8-27.) DuBois, WR. Bovine viral diarrhea virus: an update. Tennessee Veterinary Medical Association Tennessee Cattlemen's Association Veterinary Continuing Education Meeting. Frankin, TN. October 2001. DuBois, WR. An introduction to standardized performance analysis in beef herds. Tennessee Veterinary Medical Association Tennessee Cattleman's Association Veterinary Continuing Education Meeting. Frankin, TN. October 2001. DuBois WR. On farm biosecurity measures for the cow-calf producer. Tennessee Cattleman's Association Annual Convention. Franklin , TN. October 2001. Ryan L. Royer DVM Dr. Ryan L. Royer was born and raised in Clinton, Iowa on a small beef cow-calf operation. He attended Iowa State University and received his Bachelor’s of Science degree in Animal Science in 1998, and continued at Iowa State University receiving his doctor of veterinary medicine degree in 2002. During his undergraduate studies and into veterinary school, Dr. Royer was extensively involved in swine research projects involving PRRS, SIV, M.hyo and circovirus. Upon completion of his veterinary degree, Ryan became an associate with the Cresco Veterinary Clinic in Cresco, IA, practicing traditional mixed animal medicine. In 2003, he moved to Elkader, another town in northeast Iowa, where he became a partner of the Elkader Veterinary Clinic, LLC. Dr. Royer’s primary focus was dairy and swine production medicine. During his time with the Elkader Veterinary Clinic, Dr. Royer was involved with several Johne’s research projects in collaboration with researchers at Iowa State University. Ryan and his wife, Jennifer, live in Dalhart with their 3 children, Daniel, Lizzie, and Katie. Dr. Royer’s current area’s of interest are dairy herd health programs, swine herd health programs, and food animal research. His professional memberships and publications and presentations are listed below. PROFESSIONAL ORGANIZATIONS: American Veterinary Medical Association (2002 – present) Iowa Veterinary Medical Association (2002 – present) American Association of Swine Veterinarians (2002 – present) American Association of Bovine Practitioners (2002 - present) Professional Publications and Presentations: Ratree Platt, DVM, PhD; James A. Roth, DVM, PhD, Ryan L. Royer, DVM, Charles O. Thoen, DVM, PhD. Monitoring responses by use of 5-color flow cytometrty in subsets of peripheral T cells obtained from cattle inoculated with a killed Mycobacterium avium subsp paratuberculosis vaccine. AJVR, Vol 67, No. 12, December 2006. Fenaux M, Halbur PG, Haqshenas G, Royer R, Thomas P, Nawagitgul P, Gill M, Toth TE, Meng X-J. Cloned genomic DNA of type 2 porcine circovirus is infectious when injected directly into the liver and lymph nodes of pigs: Characterization of clinical disease, virus distribution, and pathologic lesions. J or Virol 76(2):541-551, 2002. Royer RL, Nawagitgul P, Halbur PG, Paul PS. Susceptibility of porcine circovirus type 2 to commercial and laboratory disinfectants. Journal of Swine Health and Production 9(6):281-284, 2001. Thanawongnuwech R, Brown GB, Halbur PG, Roth JA, Royer RL, Thacker BJ: Pathogenesis of porcine reproductive and respiratory syndrome virus-induced increase in susceptibility to Streptococcus suis infection. Veterinary Pathology 37:143-152, 2000. XJ Meng, PG Halbur, JS Haynes, TA Tsareva, JD Bruna, RL Royer, RH Purcell, SU Emerson. Experimental infection of pigs with the newly identified swine hepatitis E virus, but not with human strains of HEV. Archives of Virology 143: 1405-1415, 1998. Thanawongnuwech R, Halbur PG, Ackerman MR, Thacker EL , Royer RL: Effects of low (modified – live virus vaccine) and high (VR-2385) virulence strains of porcinereproductive and respiratory syndrome virus (PRRSV) on pulmonary clearance of copper particles in pigs. Veterinary Pathology 35: 398-406,1998. Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. In Proceedings of the Collaboration between College of Veterinary Medicine, ISU and Faculty of Veterinary Science, Chulalongkorn University, August 1-8, 2001,pp41-44. Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. In Proceedings of American Association of Swine Practitioners 31.45 Halbur PG, Sorden SD, Royer RL, Bruna J: Investigation into the severe acute PRRS outbreaks.1997 Iowa State University Swine Research Reports, pp150-151. Thanawongnuwech R, Halbur PG, Royer RL, Bruna J: PRRS virus-induced damage to intravascular macrophages. 1997 Iowa State University Swine Research Reports, pp 152-153. HF Rotto, PG Halbur, PS Paul, SS Schuchaskie, RL Royer. Effects of Different Strains of Porcine Reproductive and Respiratory Syndrome Virus on Lymph Node Morphology. In Proceedings of American Association of Veterinary Laboratory Diagnosticians, p30, October, 1997. Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. Presented at the Spring Conference of the Iowa Veterinary Medical Association, 2000, Ames, IA. Royer RL, Nawagitgul P, Halbur PG, Paul PS: 2000. Susceptibility of porcine circovirus to several commercial and laboratory disinfectants. Presented at the Collaboration between College of Veterinary Medicine, ISU and Faculty of Veterinary Science, Chulalongkorn University, 2001, Bangkok, Thailand. NorthEast Iowa Dairy Days – 2004. Proper Foot Health – Maintenance and Pathology. Clayton & Fayette County Land-O-Lakes/Purina Feeds Barn Meeting – 2007. Observations in the Transition Pen from a Practicing Veterinarian.