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 and Chair of the Department of Population Medicine, OVC, University of Guelph. Todd has taught 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 240 peer-reviewed articles on several aspects of dairy health management including transition cow metabolic disease, including ketosis, hypocalcemia, and rumen acidosis. More recently he has focused research in the area of dairy welfare including strategies for minimizing pain in dairy animals and improving the welfare of cull dairy animals. He has spoken on many of these aspects of dairy health management in several countries including Italy, Portugal, Spain, Mexico, Turkey, Russia, Argentina, Australia, and Japan. Todd was on study leave with Dr. Ian Lean at Scibus in Camden, Australia in 2007 working on learning meta-analysis methods. He has received several awards in recognition of his work (see below).

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
  • Management of cull dairy cows

Current Graduate Students

Former Graduate Students


  • Cassie Reedman
  • Dave Renaud
  • Elise Tatone
  • Terri Ollivett
  • Christine Murray
  • Khaled Gohary
  • Nathalie Newby


  • Taika von Königslow
  • Charlotte Winder
  • Jessica Gordon
  • Gerardo Quiroz-Rocha (Pathobiology)
  • Steve Hendrick
  • Randy Dingwell
  • Stephen LeBlanc


  • Nicole Berdusco
  • Joanne Marshall
  • Antonio DeGroot
  • Maggie Williamson
  • Allison Moorman
  • Jennifer Reynen
  • Anneliese Heinrich
  • Mark Carson

Research Interests

I have been a member of the OVC Ruminant Field Service for over 25 years where I have participated in both planned herd health activities as well as emergency farm calls including out of hours service. Although no longer involved in the daily clinical activities, I am still teaching in planned on-farm elective rotations.


  • Metabolic Disease - Food Animal Medicine and Surgery VETM**4460
  • Senior Dairy Elective Rotations:
    • Dairy Welfare
    • Dairy Nutrition
    • Dairy Herd Problem Solving
    • Food Animal Diagnostic Pathology
  • Dairy Health Management Graduate Course POPM*6400

Professional Experience & Honours

Prize / Awards

  • OABP Award of Excellence, 2021
  • Journal of Dairy Science Club 100 Award, 2019
  • CABV Metacam 20 Bovine Welfare Award, 2018 Canadian Association of Bovine Veterinarians
  • January 2012 - ) Canadian Veterinary Medical Association, The Merck Veterinary Award 2012


  • JDS Top 100 Author for 2022 Journal of Dairy Science
  • paper in top 100 cited in Journal for 2019 (awarded in 2022). J Dair Sci. 102:4498-4505 Renaud et al, 2019.
  • JDS Top 100 Author for 2018 Journal of Dairy Science
  • paper among 100 most cited since 2016: J. Dairy Sci. 100: 1308-1318. Tatone et al, 2017
  • Highly Cited Researcher: 2016 and 2017 Clarivate Analytics
  • Editor's Choice (August) for article: Clinical trial of local anesthetic protocols for acute pain associated with caustic paste disbudding in dairy calves, 2017. Journal of Dairy Science
  • Editor's Choice (October) for article: Effect of prepartum administration of recombinant bovine somatotropin on health and performance of lactating dairy cows, 2014 Journal of Dairy Science
  • Thomson Reuters Highly Cited Researcher (Agricultural Sciences), 2014
  • Listed in Thomson Reuters 2014 World's Most Influential Scientific Minds (January 2014)

Selected Publications

Google Scholar