Internal Medicine Clinical Team

Our internal medicine team comprises board-certified faculty/clinicians, nurses and technicians, as well as residents, interns and students. We pride ourselves in providing excellent care and a compassionate environment for our clients and patients.


Title Area(s) of Specialty
 Mary Beth Callan, VMD, Penn Vet, internal medicine Mary Beth Callan, VMD, DACVIM
  • Professor, Internal Medicine
  • Hematology
  • Transfusion medicine
 Rebeka Hess, Penn Vet, internal medicine Rebecka S. Hess, DVM, DACVIM
  • Associate Professor, Medicine
  • Chief, Medicine Section
  • Internal Medicine
  • Diabetes
 Meryl Littman Meryl P. Littman, VMD, DACVIM
  • Associate Professor, Medicine
  • Internal Medicine
  • Lyme Disease
 Nicola Mason, Penn Vet, internal medicine Nicola Mason, BVM, PhD, MRCVS, DACVIM
  • Assistant Professor, Medicine
  • Internal Medicine
  • Canine Cancer
 Julie Callahan-Clark, Penn Vet, internal medicine Julie Callahan Clark, DVM, DACVIM
  • Lecturer
  • Internal Medicine
 Penn Vet, Dr. JD Foster, internal medicine JD Foster, VMD, DACVIM (SAIM)
  • Lecturer
  • Internal Medicine
  • Hemodialysis
 Ariel Mosenco, Penn Vet, internal medicine Ariel Mosenco, DVM, DACVIM
  • Staff Veterinarian
  • Internal Medicine
  • Nutrition
 Mark Rondeau, Penn Vet, internal medicine Mark Rondeau, DVM, DACVIM
  • Staff Veterinarian
  • Internal Medicine


Abigail Bertalan, VMD, Penn Vet, internal medicine Abigail Bertalan, VMD
 Lisa Hann, Penn Vet, internal medicine Lisa Hann, DVM
 Jessica Midence, Penn Vet, internal medicine Jessica Midence, DVM
Melissa Tollett, Penn Vet, internal medicine Melissa Tollett, DVM
Carolyn Gross, Penn Vet, internal medicine
Carolyn Gross, DVM
 Talia Guttin, Penn Vet, internal medicine Talia Guttin, VMD
Frances Hurell, BVSc, Resident, Penn VetFrances Hurrell, BVSc

Barbara Tauk

Barbara Tauk, DVM
Dr. Hathaway Fiocchi Hathaway Fiocchi, DVM
Dr. Kristen Kelly
Kristen Kelly, DVM
Dr. Christina Marino  Christina Marino, DVM
Dr. Eileen Seage  Eileen Seage, VMD


NursIng Staff
NameArea(s) of Specialty
Victoria Anders CVT, VTS (SAIM) Internal Medicine
Paula Emma, CVT Endoscopy and Internal Medicine
Jennifer Elenback, CVT, VTS (SAIM) Internal Medicine
Charlotte M. Higgins, CVT Nutrition Support
Ali McKenna, CVT Internal Medicine