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Executive Board Officers & Members

The American Heartworm Society was founded in early 1974 by a group of veterinary practitioners and scientists concerned about heartworm disease. Since then, the Society has continued to thrive and grow.  Active membership is open to all veterinarians and scientists with interests in any aspect of heartworm disease.  Membership as a Subscriber or Student Member is also available to other individuals interested in keeping abreast of the latest developments in this area.

The American Heartworm Society is governed by an Executive Board made up of veterinary practitioners, academicians and researchers. Executive board members are actively involved in the day-to-day operations of the Society and volunteer hundreds of hours of time in the Society’s service. Only members in private clinical practice may serve as President.

The American Heartworm Society is an international organization, with members from five continents and 13 countries.



Chris Duke


Chris Duke, DVM, is a practitioner and co-owner of Bienville Animal Medical Center in Ocean Springs, Mississippi.
[email protected]


Immediate Past President

Christopher J. Rehm, Sr., DVM, is the owner of Rehm Animal Clinics of Mobile and Baldwin counties, four small animal clinics in south Alabama.
[email protected] 


Vice President

Doug Carithers, DVM, is Director of Applied Research and Publications at Boehringer Ingelheim in Duluth, Georgia.
[email protected]



Elizabeth Clyde, DVM, is the owner of Clyde’s Animal Clinic in Mattoon, Illinois and the Animal Family Vet Care Center of Paris in Paris, Illinois.
[email protected]



Brian DiGangi, DVM, MS, DABVP (Canine & Feline Practice, Shelter Medicine Practice), is a Senior Director of Shelter Medicine at the ASPCA and is based out of Gainesville, Florida.
[email protected]


Research Chair

Charles Thomas (Tom) Nelson, DVM, is Medical Director at the Animal Medical Centers of N.E. Alabama, based in Anniston, Alabama.
[email protected]


Executive Board Members

AngeleBiceAngele Bice, DVM is owner of Summerville Pet Clinic in Summerville, South Carolina and also practices shelter medicine part-time at Dorchester Paws and the Charleston Animal Society.
[email protected]

MarisaAmesMarisa Ames, DVM, DACVIM (Cardiology) is an Associate Professor of cardiology at the UC Davis School of Veterinary Medicine, and AHS Triennial Symposium Program Co-Chair.
[email protected]

AndyMoorheadAndrew Moorhead, DVM, MS, PhD, DACVM (Parasitology) is an Associate Professor at the University of Georgia and is Director and Primary Investigator of the Filariasis Research Reagent Resource Center in Athens, Georgia.
[email protected]

JenniRizzoJennifer Rizzo, DVM, is an Emergency Veterinarian at Blue Pearl Pet Hospital in Gainesville, FL, and Founder of Lone Star Veterinary Academy.
[email protected]

LindsayStarkeyLindsay Starkey, DVM, PhD, DACVM (Parasitology), is Assistant Professor of Parasitology in the Department of Pathobiology at Auburn University’s College of Veterinary Medicine in Auburn, Alabama.
[email protected]

Bianca Zaffarano

Bianca Zaffarano, DVM is the Clinical Associate Professor Emeritus at Iowa State University, Ames, Iowa.
[email protected]

Ex-Officio - Non-Voting

ChrisAdolphChris Adolph, DVM, MS, DACVM (Parasitology), Veterinary Specialist (Parasitology) at Zoetis in Tulsa, Oklahoma.
[email protected]


JohnMcCall2John W. McCall, MS, PhD, is Professor Emeritus in the Department of Infectious Diseases at the University of Georgia College of Veterinary Medicine in Athens, Georgia.
[email protected]

C.RoyalChristine Royal, DVM, is Director of Veterinary Professional Services, Companion Animal and Equine, at Merck Animal Health in Tallahassee, Florida.

[email protected]heartwormsociety.org


Tony Rumschlag, DVM, is Director of Consulting Veterinarians, Companion Animal, at Elanco/Lilly Companion Animal Health in Greenfield, Indiana.

[email protected]

von Simson

Cristiano von Simson, DVM, MBA,is Director of Marketing and Veterinary Services, at Virbac North America in Westlake, Texas.

[email protected]heartwormsociety.org

AHS Association Management Team

Sease Management, LLC serves as the Association Management Team of the American Heartworm Society. Please contact the following persons for specific needs:

Lisa Scott
Partner, Sease Management, LLC
Director of the Association Management Team
Sponsor Contact, Triennial Symposium Coordinator, General Information
[email protected]

Sonya Hennessy
Partner, Sease Management, LLC
Financial Inquiries, Membership, Heartworm University
[email protected]

Public Relations

Sue O'Brien
SKO’Brien Communications
[email protected]


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