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


Professor, Department of Clinical Studies - Philadelphia, University of Pennsylvania School of Veterinary Medicine

Chief, Section of Cardiology, Veterinary Hospital of the University of Pennsylvania, School of Veterinary Medicine

Diplomate, American College of Veterinary Internal Medicine, Cardiology

Clinical Specialties: Cardiology, Cardiac Examinations, Echocardiograms, ECG, Non-invasive & Invasive Surgeries,
Research Areas: Animal models of heart disease Heart Disease Myxomatous mitral valve disease Cardiac biomarkers Clinical trials Epidemiology Biostatistics Diuretic resistance
PubMed Link
Contact Information:
Department of Clinical Studies-Philadelphia
Ryan Veterinary Hospital of the University of Pennsylvania
School of Veterinary Medicine
University of Pennsylvania
3900 Spruce St.

Canine and feline models of heart disease
Molecular mechanisms of myxomatous mitral valve disease
Diuretic resistance
Epidemiology and biostatistics

Cardiac biomarkers (troponin, natriuretic peptides [BNP, ANP])
Diuretic resistance
Clinical trials
Serotonin signaling and myxomatous valve disease
Animal models of heart disease and heart failure
Epidemiology and biostatistics

Hezzell M J, Rush J E, Humm K, Rozanski E A, Sargent J, Connolly D J, Boswood A, Oyama M A Differentiation of Cardiac from Noncardiac Pleural Effusions in Cats using Second-Generation Quantitative and Point-of-Care NT-proBNP Measurements. Journal of veterinary internal medicine / American College of Veterinary Internal Medicine 30: 536-42, 2016.

Solter Philip F, Oyama Mark A, Machen Maggie C, Trafny Dennis J, Sisson D David Detection by ELISA of C-terminal proBNP in plasma from cats with cardiomyopathy. Veterinary journal (London, England : 1997) 206: 213-7, 2015.

Pouchelon J L, Atkins C E, Bussadori C, Oyama M A, Vaden S L, Bonagura J D, Chetboul V, Cowgill L D, Elliot J, Francey T, Grauer G F, Fuentes V Luis, Moise N Sydney, Polzin D J, Van Dongen A M, Van Israël N Cardiovascular-renal axis disorders in the domestic dog and cat: a veterinary consensus statement. The Journal of small animal practice 56: 537-52, 2015.

Oyama Mark A Perioperative Monitoring of Heart Rate and Rhythm. The Veterinary clinics of North America. Small animal practice 45: 953-63, 2015.

Oyama Mark A Using Cardiac Biomarkers in Veterinary Practice. Clinics in laboratory medicine 35: 555-66, 2015.

Cremer S E, Moesgaard S G, Rasmussen C E, Zois N E, Falk T, Reimann M J, Cirera S, Aupperle H, Oyama M A, Olsen L H Alpha-smooth muscle actin and serotonin receptors 2A and 2B in dogs with myxomatous mitral valve disease. Research in veterinary science 100: 197-206, 2015.

Cremer, Signe E; Kristensen, Annemarie T; Reimann, Maria J; Eriksen, Nynne B; Petersen, Stine F; Marschner, Clara B; Tarnow, Inge; Oyama, Mark A; Olsen, Lisbeth H. Plasma and serum serotonin concentrations and surface-bound platelet serotonin expression in Cavalier King Charles Spaniels with myxomatous mitral valve disease. American Journal of Veterinary Research 76: 520-31, 2015.

Cremer S E, Zois N E, Moesgaard S G, Ravn N, Cirera S, Honge J L, Smerup M H, Hasenkam J M, Sloth E, Leifsson P S, Falk T, Oyama M A, Orton C, Martinussen T, Olsen L H Serotonin markers show altered transcription levels in an experimental pig model of mitral regurgitation. Veterinary journal (London, England : 1997) 203: 192-8, 2015.

Fox, P R; Oyama, M A; Hezzell, M J; Rush, J E; Nguyenba, T P; DeFrancesco, T C; Lehmkuhl, L B; Kellihan, H B; Bulmer, B; Gordon, S G; Cunningham, S M; MacGregor, J; Stepien, R L; Lefbom, B; Adin, D; Lamb, K. Relationship of plasma N-terminal pro-brain natriuretic peptide concentrations to heart failure classification and cause of respiratory distress in dogs using a 2nd generation ELISA assay. Journal of Veterinary Internal Medicine 29: 171-9, 2015.

Machen, Maggie C; Oyama, Mark A; Gordon, Sonya G; Rush, John E; Achen, Sarah E; Stepien, Rebecca L; Fox, Philip R; Saunders, Ashley B; Cunningham, Suzanne M; Lee, Pamela M; Kellihan, Heidi B. Multi-centered investigation of a point-of-care NT-proBNP ELISA assay to detect moderate to severe occult (pre-clinical) feline heart disease in cats referred for cardiac evaluation. Journal of Veterinary Cardiology 16: 245-55, 2014.

DVM (Doctor Veterinary Medicine) University of Illinois, 1994

MSCE (Masters of Science in Clinical Epidemiology) University of Pennslyvania, 2015