Research Interests

Veterinary Clinical Pharmacology

• Drug residues in products of food animals; food safety
• Extra label drug use in food producing animals
• Regulation of drug use in veterinary patients
• Drug depletion studies in food producing animals
• Pharmacokinetic studies
• Evaluation and veterinary applications of drug delivery systems
• Drug and analyte assay (Mass Spec, HPLC, ELISA, EIA)
• Clinical trials for regulatory approval of veterinary drugs
• Clinical research including exploratory/discovery studies

Current Graduate Students

Samantha
Lyster

MSc

Philip
Russell

MSc

Selected Publications

• Reimann, J., Dewey, C., Bateman, S. W., Kerr, C., & Johnson, R. (in press, 2016). Perioperative analgesic use by Ontario veterinarians, 2012. Canadian Veterinary Journal.
• Johnson, R., Kerr, C., Enouri, S., Modi, P., Lascelles, D., delCastillo J (in press, 2016). Pharmacokinetics of Liposomal Encapsulated Buprenorphine Suspension Following Subcutaneous Administration to Cats. Journal of Veterinary Pharmacology and Therapeutics. \
• Boison, J., Dowling, P., Johnson, R., & Kinar, J. (2016). Analysis of phenylbutazone residues in horse tissues with and without enzyme-hydrolysis by LC-MS/MS. Drug Testing and Analysis, 8, 535-538.
• O'Sullivan, T., Johnson, R., Poljak, Z., Gu, Y., Delay, J., Friendship R. (2016). An experimental study with a vaccine strain of porcine reproductive and respiratory syndrome virus to determine effects on viremia assessed by reverse transcriptase-polymerase chain reaction in pigs fed rations medicated with tilmicosin or non-medicated. Journal of Swine Health and Production, 24 (2), 81-92.
• Sanchez, A., Valverde, A., Sinclair, M., Moseley, C., Singh, A., Mutsaers AJ, Hanna B, Gu Y, Johnson R.(2016). The pharmacokinetics of DPH after the administration of a single intravenous or intramuscular dose in healthy dogs. Journal of Veterinary Pharmacology and Therapeutics., doi: 10.1111/jvp.12293.
• Enouri, S., DeKroon, K., Friendship, R., Schrier, N., Dowling, P., Johnson R. (2015). Depletion of bromadiolone in tissues of hogs following oral exposure. Journal of Swine Health and Production, 23 (6), 298-305.
• Hsu, K., Pinard, C., Johnson, R., Allen, D., Kukanich, B., Nykamp S (University of Guelph, Canada). (2015). Systemic absorption and adverse ocular and systemic effects after topical ophthalmic administration of 0.1% diclofenac to healthy cats.  American Journal of Veterinary Research, 76 (3), 253-265.
• Keating, S., Kerr, C., MacDonell, W., Valverde, A., Johnson, R., Knych H, Edginton A (2015). Effects of acepromazine or dexmedetomidine on fentanyl disposition in dogs during recovery from isoflurane anesthesia. Veterinary Anaesthesia and Analgesia, 43 (1), 35-43.
• Sabatini, C.F., O'Sullivan, M.L., Valcour, J.E., Sears, W., & Johnson, R. (2013).  Effects of Injectable Anesthetic Combinations on Left Ventricular Function and Cardiac Morphology in Sprague–Dawley Rats.   Journal of the American Association for Laboratory Animal Science, 52 (1), 34-43.
• Hewson, J., Johnson, R., Arroyo, L.G., Diaz-Mendez, A., Ruiz-Lopez, J.A., Gu, Y., Del Castillo, J.R. (2013).  Comparison of continuous infusion with intermittent bolus administration of cefotaxime on blood and cavity fluid drug concentrations in neonatal foals.   Journal of Veterinary Pharmacology and Therapeutics, 36 (1), 68-77.
• Gianotti, G., Valverde, A., Sinclair, M., Dyson, D.H., Gibson, T., Johnson, R. (2012).  Prior determination of baseline isoflurane minimum alveolar concentration (MAC) does not influence the effect of ketamine on MAC in rabbits.   The Canadian Veterinary Journal, 76 (4), 261-267.
• Boudreau, A.E., Bersenas, A.M., Kerr, C.L., Holowaychuk, M.K., & Johnson, R. (2012).  A comparison of 3 anesthetic protocols for 24 hours of mechanical ventilation in cats.   Journal of Veterinary Emergency and Critical Care, 22 (2), 239-252.
• McLelland, D.J., Barker, I.K., Crawshaw, G., Hinds, L.A., Spilsbury, L., Johnson, R (University of Guelph, Canada) (2011).  Single-dose pharmacokinetics of oxytetracycline and penicillin G in tammar wallabies (Macropus eugenii).   Journal of Veterinary Pharmacology and Therapeutics, 34 (2), 16-167.
• Washburn, K., Johnson, R., Clarke, C., & Anderson, K. (2010).  Distribution of ceftiofur into Mannheimia haemolytica-infected tissue chambers and lung after subcutaneous administration of ceftior crystalline free acid sterile suspension.   Journal of Veterinary Pharmacology and Therapeutics, 33 (2), 141-146.