Sonja Fonfara

Sonja Fonfara head shot

Associate Professor

DVM, Dr med vet, PhD, Docent, PGCertHE, CertVC, Diplomate ECVIM (Cardiology)
 Office: CS 2127
 519-824-4120 Ext. 54061



I am board certified in companion animal cardiology from the European College of Veterinary Internal Medicine. After graduating from the University of Veterinary Medicine in Hanover in 1995, I obtained a doctoral thesis in Veterinary Pathology at the University of Giessen. This was followed by several years in a first opinion practice, where I found my love for cardiology. To develop my research skills, I took the opportunity of a postdoctoral research project in marine mammal immunology at the GKSS Research Centre and University of Kiel. 
Missing clinical work and wanting to pursue my cardiology interest, I moved to the UK in 2006 to undertake an internship and subsequently a residency in veterinary cardiology at the Small Animal Teaching Hospital at the University of Liverpool. I since have worked as lecturer and senior lecturer at the Universities in Liverpool and Bristol, obtained a PhD and was granted a docent in Small Animal Cardiology at the University of Helsinki. In February 2016, I joined the team at the University of Guelph. 

Research Interests

My research intererst is in cardiac remodelling associated with ageing and in cardiac disease. My team at the OVC in Guelph consists of:

  • Dr. Shari Raheb, my colleague and Clinical Studies faculty member, 
  • Dr. Andrew Chong and Dr. James Yan, DVSc students,
  • Jessica Joshua and Dr. Ananda Pires, PhD students,
  • Ritu Verma and Oviya Subsanthirabose, MSc students,
  • Joline Attala, MBS student.

We have a close collaboration with Prof. Jeff Caswell from the Department of Pathobiology of the OVC, and with Prof. Anja Kipar from the Institute of Veterinary Pathology of the University of Zurich. We have further collaborations with Prof. Maria Wiberg from the University of Helsinki and Dr. Domingo Casamian Sorrsal from the University in Valencia. 

Our research is supported by NSERC and OVC Pet Trust, our ongoing research projects include:

  • MicroRNA profiles as determinants of clinical and pathological outcomes in feline hypertrophic cardiomyopathy (supported by NSERC and OVC Pet Trust)

  • The influence of age, sex and HCM on myocardial gene activation in cats (supported by NSERC and OVC Pet Trust)

  • Does age influence cardiac structure and function in cats? (supported by OVC Pet Trust)

  • Novel circulating markers for feline hypertrophic cardiomyopathy (supported by OVC Pet Trust)

  • Pathogenesis of feline cardiomyopathies (project of Dr. Lea Schurna, University of Zurich)  


MSc and PhD opportunities are available in our lab.  



Current Graduate Students

  • Andrew Chong - DVSc


Selected Publications

Colpitts, M.E., Caswell, J.L., Monteith, G., Joshua, J., O'Sullivan, M.L., Raheb, S., Fonfara, S. (2022). Cardiac gene activation varies between young and adult cats and in the presence of hypertrophic cardiomyopathy. Res Vet Sci 152, 38-47

Monne Rodriguez, J. M., Fonfara, S., Hetzel, U., Kipar, A. (2022). Feline hypertrophic cardiomyopathy: reduced microvascular density and involvement of CD34+ interstitial cells. Vet Pathol, 59: 269-283.

Fonfara, S., Kitz, S., Monteith, G., Hahn, S., Kipar, A. (2021). Myocardial transcription of inflammatory and remodeling markers in cats with hypertrophic cardiomyopathy and systemic diseases associated with an inflammatory phenotype. Res Vet Sci, 136: 484-494

Gasperini, S., Fonfara, S., Kitz, S., Hetzel, U., Kipar, A. (2020). Canine dilated cardiomyopathy: diffuse remodeling, focal lesions and the involvement of macrophages and new vessel formation. Vet Pathol, 57(3): 397-408-575

Kitz, S., Fonfara, S., Hahn, S., Hetzel, U., Kipar, A. (2019). Feline Hypertrophic cardiomyopathy: The consequence of cardiomyocyte-initiated and macrophage-driven remodeling processes? Vet Pathol, 56(4): 565-575.

Malbon A.J., Fonfara, S., Meli, M.L., Hahn, S., Egberink, H., Kipar A. (2019). Feline Infectious Peritonitis as a systemic inflammatory disease: Contribution of Liver and Heart to the pathogenesis. Viruses 11, 1144; doi:10.3390/v11121144.

Pires, A., Raheb, S., Colpitts, M.E., Chong, A., O’Sullivan, M.L., Fonfara, S. (2022). Heart rate distribution in dogs with third degree atrioventricular block and rate responsive pacemakers. J Vet Cardiol, 43:70-80.

Chong, A., Appleton, M., Casamián-Sorrosal, D., Raheb, S., O’Sullivan, M.L., Pires, A., Fonfara, S. (2022). Total Bilirubin is an Independent Predictor of Death in Dogs with Degenerative Valvular Disease and Dilated Cardiomyopathy. J Vet Cardiol, 43:10-26.

Colpitts, M.E., Fonfara, S., Monteith, G., Pires, A.R., Wong, A., Raheb, S., O’Sullivan, M.L. (2021). Characteristics and outcomes of cats with and without pacemaker placement for high-grade atrioventricular block. J Vet Cardiol, 34: 37-47.

Morgan, KRS., Monteith, G., Raheb, S., Colpitts, M., Fonfara S. (2020). Echocardiographic parameters for the assessment of congestive heart failure in dogs with myxomatous mitral valve disease and moderate to severe mitral regurgitation. Vet J 263: doi: 10.1016/j.tvjl.2020.105518.

Lam, C., Casamian-Sorrosal, D., Monteith, G., Fonfara, S. (2019). Heart-fatty acid binding protein in dogs with degenerative valvular disease and dilated cardiomyopathy. Vet J, 244: 16-22.

Search PubMed for additional publications by Dr. Fonfara.