New Bolton Center Kennett Square, PA
Emergencies & Appointments:
Ryan Hospital Philadelphia, PA


Board Certified – American College of Veterinary Internal Medicine

Associate Professor of Medicine, Section of Field Service, New Bolton Center, University of Pennsylvania

Clinical Specialties: Internal medicine, infectious disease, lameness, herd health
Research Areas: Strangles, Streptococcus equi infections in horses, Equine infectious Disease
PubMed Link
Contact Information:
University of Pennsylvania
School of Veterinary Medicine
Department of Clinical Studies
New Bolton Center
382 West Street Road

Equine Infectious Disease, especially Streptococcus equi equi (Strangles), Vaccination

20+ years of equine clinical practice including equine internal medicine residency training (UCDAVIS) from 2001-2004 and sports medicine/lameness training with the PennVet NBC Sports Medicine Department 2004-2005. Currently I practice all aspects of equine clinical practice including internal medicine, infectious disease, lameness, and herd health.

Boyle AG, Rankin SC, O’Shea K, Stefanovski D, Peng J, Song J, Bau H. Detection of Streptococcus equi subsp equi in Convalescent Guttural Pouch Lavage Samples Using a LAMP Microfluidic Device. JVIM : , 2021.

Cianci J, Boyle AG, Stefanovski D, Biddle A. Lack of association between barometric pressure and incidence of colic in equine academic ambulatory practice. J of Eq Vet Sci 97: , 2021.

Boyle AG, Mitchell C, Stefanovski D, Waller AS. Horses Vaccinated with Live Attenuated Intranasal Strangles Vaccine Seroconvert to SEQ2190 and SeM. EVJ : , 2021.

Boyle AG*, O’Shea K, Stefanovski D, Rankin SC Propidium Monoazide-quantitative Realtime Polymerase Chain Reaction for the Detection of Viable Streptococcus equi Havemeyer Foundation Workshop Getting to Grips with Strangles and other Streptococcal Diseases : , 2019.

Boyle AG Streptococcus equi (Strangles) Large Animal Internal Medicine 6: , 2019.

Boyle AG Streptococcus equi Blackwell’s Five Minute Veterinary Consult Equine 3: , 2019.

Cole S, Stefanovski D, Towl S, Boyle AG Factors associated with prolonged treatment days, increased veterinary visits and complications in horses with subsolar abscesses. Vet Rec 184: 251, 2019.

Boyle AG, Timoney JF, Newton JR, Hines MT, Waller AS, Buchanan BR Streptococcus equi Infections in Horses: Guidelines for Treatment, Control, and Prevention of Strangles-Revised Consensus Statement Vet Intern Med. 32: 633-647, 2018.

Boyle AG, Stefanovski D, Rankin SC. Determining optimal sampling site for Streptococcus equi subsp equi carriers using loop-mediated isothermal amplification BMC Vet Research 13: , 2017.

Boyle Ashley G, Boston Ray C, O'Shea Kathleen, Young Sheri, Rankin Shelley C Optimization of an in vitro assay to detect Streptococcus equi subsp. equi. Veterinary microbiology 159: 406-10, 2012.

Boyle Ashley G, Sweeney Corinne R, Kristula Michaela, Boston Ray, Smith Gary Factors associated with likelihood of horses having a high serum Streptococcus equi SeM-specific antibody titer. Journal of the American Veterinary Medical Association 235: 973-7, 2009.

Duffee LR, Stefanovski D, Boston RC, Boyle AG Predictor variables for Streptococcus equi subspecies equi diagnosis and complications in horses: 108 cases ( 2005-2012) JAVMA 247: 1161-8, 2015.

Boyle AG, Rankin SC, Duffee L, Boston RC, Aceto HW. S. equi detection PCR assay for equine nasopharyngeal and guttural pouch wash samples. JVIM 30: 276-281., 2016.

Boyle AG Strangles and its complications. Equine Vet Education 29: 149-157, 2017.

Boyle AG, Rankin SC, Morris DO Prevalence of methicillin resistant Staphylococcus aureus from equine nasopharyngeal and guttural pouch wash samples. J Vet Intern Med. : , 2017.

Boyle AG, Smith MA, Boston RC, Stefanovski D SeM titers after natural outbreaks of Streptococcus equi equi in horses: a case-control study JAVMA 250: 1432-1439, 2017.

BA Smith College, 1996

DVM Cornell University, 2000


Board Certified – American College of Veterinary Internal Medicine

Littleton Large Animal Clinic (2000 to 2001)

University of California, Davis (2001 to 2004)
Resident in Large Animal Internal Medicine