Todd Duffield

Todd Duffield

Department Chair | Professor

DVM, DVSc (Guelph)
 Office: Stewart Bldg. 2409A
 519-824-4120 Ext. 54057



Todd graduated from the Ontario Veterinary College (OVC), University of Guelph in 1990 (DVM) and worked for 4 years in a large dairy practice in eastern Ontario, Canada.  He returned to OVC in 1994 and completed a Doctor of Veterinary Science (DVSc) degree in 1997.  He is currently a Professor in the Department of Population Medicine, OVC, University of Guelph.  Todd teaches in all years of the undergraduate veterinary program.  He is actively involved in dairy research, graduate supervision and teaching. He has authored or co-authored over 160 peer-reviewed articles on several aspects of dairy health management including transition cow metabolic disease, use of monensin in dairy cattle, production limiting diseases (Johne’s disease, Neospora abortion), and more recently strategies for minimizing pain in cattle.   He has spoken on many of these areas of dairy health management in several countries including Italy, Portugal, Spain, Mexico, Turkey, Russia, Argentina, Australia, and Japan. Todd was on sabbatic leave with Dr. Ian Lean at Strategic Bovine Services in Camden, Australia in 2007 working on learning meta-analysis methods.   He is the recipient of the 2012 CVMA Merck Award for contributing significantly to the advancement of herd health management in Canada.  Todd was recently honoured as a Thomson Reuters and Clarivate Highly Cited Researcher.

Research Interests

  • Metabolic Disease in Dairy Cows - including ketosis, hypocalcemia, and subacute rumen acidosis
    • etiology, risk factors, treatment, prevention
  • Impact of Ionophores in dairy cattle
  • Impact, prevention, and management of production limiting disease (ie Neospora caninum, Johnes disease)
  • Pain management of dairy cattle including disbudding, surgery, dystocia

Current Graduate Students

  • Nicole Berdusco - MSc

Research Interests

I have been a member of the OVC Ruminant Field Service for over 20 years where I have participated in both planned herd health activities as well as emergency farm calls including out of hours service.


  • Health Management 1 VETM**3400
  • Metabolic Disease - Food Animal Medicine and Surgery VETM**4460
  • Senior Core & Dairy Elective Rotations
    - Ruminant Health Management (RHM) - Food Animal and Rural Community Practice
    - RHM - Dairy Rotation
    - RHM - Dairy Nutrition
    - RHM - Dairy Herd Problem Solving
    - Food Animal Diagnostic Pathology
  • Dairy Health Management Graduate Course POPM*6400

Selected Publications

Search PubMed for additional publications by Dr. Duffield.