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Kansas State University

Faculty

 

Deon van der Merwe

 

Deon van der Merwe
BVSc 1994, University of Pretoria
BSc (Hons) (Wildlife Management) 1998, University of Pretoria
MSc (Vet Sc) 2000, University of Pretoria
PhD (Comparative Biomedical Sciences) 2005, North Carolina State University
 
Associate Professor
Head: Toxicology Section
Kansas State Veterinary Diagnostic Laboratory
Phone: 785–532 4333
Fax: 785–532 4481
Email: dmerwe@vet.ksu.edu

 

 

Research

My research interests are varied and include aspects of environmental toxicology and ecotoxicology, the use of unmanned aircraft systems in agricultural and environmental applications, mathematical and spatial models in toxicology, and veterinary diagnostics.

I have been involved in applications of small unmanned aircraft systems since 2008, with a particular interest in the unique challenges associated with deploying wide angle sensors on low-flying aircraft. It includes image processing to extract useable information from raw sensor data. Specific applications include the detection and quantification of toxic algal blooms, the determination of plant poisoning risk, habitat and biodiversity assessment, crop health assessment, and applications in intensive and extensive animal production systems. More information can be found here: http://www.k-state.edu/measa/

We live in a chemical world, and under certain conditions exposure to chemicals can be harmful, depending on the type of chemical and the level of exposure. My work in environmental toxicology and ecotoxicology is focused on the movement of chemicals in the environment that determines the exposure to various organisms.

My work in mathematical modeling involves studies of the absorption of chemicals into the body following skin exposure. This work includes efforts to better understand the mechanisms of absorption, as well as in vitro experiments aimed at determining the rates of absorption of particular chemicals and formulations.

Plants contain biologically active compounds that can have both toxic and potentially useful effects. I am interested in the interactions between people, plants and animals where it involves plant toxicity and the use of plants as medicines. Poisonous plants often cause serious livestock losses. These losses are typically associated with specific environmental conditions related to climate, soil, the life stage of the plants and management practices. I am interested in characterizing the environmental conditions that are correlated with animal losses due to plant poisoning.

Teaching

I teach the following courses

  • Veterinary Toxicology (DMP 801)
  • Advanced Toxicology (DMP 803)
  • Ecotoxicology (DMP 804)
  • Toxins in the Biological System (DMP 805)
  • Environmental Toxicology (DMP 806)
  • Problems in Toxicology (DMP 809)
  • Diagnostic Medicine – Toxicology rotation (DMP 785)

Service

I manage the Toxicology Section of the KSU Veterinary Diagnostic Laboratory. The Toxicology Section provides diagnostic services to veterinary colleagues and the general public.

Publications

Peer-reviewed publications

Kenne G, Van der Merwe D 2013. Classification of toxic cyanobacterial blooms by Faurier-Transform infrared technology (FTIR). Advances in Microbiology 3(6)1-8.

Mahdi AJ, Van der Merwe D 2013 Dog and Cat Exposures to Hazardous Substances Reported to the Kansas State Veterinary Diagnostic Laboratory: 2009–2012. Journal of Medical Toxicology, 9(2):207-211.

Botha CJ, Coetser H, Schultz A, Labuschagne L, Van der Merwe D 2013 Spatial variation of epoxyscillirosidine concentrations in yellow tulp (Moraea pallida) in South Africa. Onderstepoort Journal of Veterinary Research, 80(1):6 pages

Sebbag L, Schmid D, Van der Merwe D 2013 Liver failure in a dog following suspected ingestion of blue-green algae (Microcystis spp.): A case report and review of the toxin. Journal of the American Animal Hospital Association, Available online: http://www.jaaha.org

Van der Merwe D, Sebbag L, Nietfeld JC, Aubel MT, Foss A, Carney E 2012 Investigation of a Microcystis aeruginosa cyanobacterial freshwater harmful algal bloom associated with acute microcystin toxicosis in a dog. Journal of Veterinary Diagnostic Investigation, 24(4):679-687.

Al-Bataneih MM, Van der Merwe D, Schultz BD, Gehring R. Molecular and Functional Identification of Organic Anion Transporter Isoforms In Cultured Bovine Mammary Epithelial Cells (BME-UV). Journal of veterinary Pharmacology and Therapeutics 35(3):209-215.

Raghavan R, Brenner K, Higgins J, Van der Merwe D, Harkin KR 2011 Evaluations of land cover risk factors for canine leptospirosis: 94 cases (2002-2009). Preventive Veterinary Medicine 101:241-249.

Van der Merwe D, Carpenter JW, Nietfeld JC, Miesner JF 2011 Adverse health effects in Canada geese (Branta canadensis) associated with waste from zinc and lead mines in the Tri-State Mining District (Kansas, Oklahoma, and Missouri, USA). Journal of Wildlife Diseases 47(3):650-660.

Al-Bataneih MM, Van der Merwe D, Schultz BD, Gehring R 2010 Tumor necrosis factor alpha increases p-glycoprotein expression in a BME-UV in vitro model of mammary epithelial cells. Journal of Veterinary Pharmacology and Therapeutics 31(8-9):506-515.

Hanzlicek A, Van der Merwe D2010. Dibucaine toxicosis in a dog. Journal of Medical Toxicology 6:44-49.

Schumm P, Scoglio CM, Van der Merwe D 2009 A network model of successive partitioning-limited solute diffusion through the stratum corneum. Journal of Theoretical Biology 262:471-477.

Al-Bataneih MM, Van der Merwe D, Schultz BD, Gehring R 2009 Cultured mammary epithelial monolayers (BME-UV) express functional organic anion and cation transporters. Journal of Veterinary Pharmacology and Therapeutics 32(5):422-428

Van der Merwe D, Tawde S, Pickrell JA, Erickson LE 2009 Nanocrystalline titanium dioxide and magnesium oxide in vitro dermal absorption in human skin. Cutaneous and Ocular Toxicology 28(2):78-82

Van der Merwe D, Tawde S 2008 Antacids in the initial management of metallic zinc ingestion in dogs. Journal of Veterinary Pharmacology and Therapeutics 32:203-206

Oliver C M, Skinner J D, Van der Merwe D 2007 Territorial behaviour in southern impala rams (Aepyceros melampus Lichtenstein). African Journal of Ecology  45(2):142-148

Spickett A M, Van der Merwe D, Matthee O 2007 The effect of orally administered Aloe marlothii leaves on Boophilus decoloratus tick burdens on cattle. Experimental and Applied Acarology 41(1-2):139-46

McGaw LJ, Van der Merwe D, Eloff JN 2007 In vitro anthelmintic, antibacterial and cytotoxic effects of extracts from plants used in South African ethnoveterinary medicine.Veterinary Journal 173(2):366-72.

Van der Merwe D, Du Plessis L 2006 Microscopic morphology of Dichapetalum cymosum (Hook.) Engl. as an aid in the identification of leaf fragments in the digestive tract of poisoned animals. Journal of the South African Veterinary Association 77(4):197-201

Van der Merwe D, Riviere J E 2006 Cluster analysis of the dermal permeability and stratum corneum/solvent partitioning of ten chemicals in twenty-four chemical mixtures in porcine skin. Skin Pharmacology and Physiology 19(4):198-206

Luseba D, Van der Merwe D 2006 Ethnoveterinary medicine practices among Tsonga speaking people of South Africa. Onderstepoort Journal of Veterinary Research 73(2):115-122

Van der Merwe D, Brooks JD, Gehring R, Baynes RE, Monteiro-Riviere NA, Riviere JE 2006 A physiologically based pharmacokinetic model of organophosphate dermal absorption. Toxicological Sciences 89(1):188-204

Van der Merwe D, Riviere J E 2005 Effect of vehicles and sodium lauryl sulphate on xenobiotic permeability and stratum corneum partitioning in porcine skin. Toxicology 206:325-335

Van der Merwe D, Riviere J E 2005 Comparative studies on the effects of water, ethanol and water/ethanol mixtures on chemical partitioning into porcine stratum corneum and silastic membrane. Toxicology In Vitro 19(1):69-77

Gehring R, Van der Merwe D, Pierce AN, Baynes RE, Craigmill AL, Riviere JE 2005 Multivariate meta-analysis of pharmacokinetic studies of ampicillin trihydrate in cattle. American Journal of Veterinary Research 66(1):108-112

Botha C J, Shakespeare A S, Gehring R, Van der Merwe D 2001 Evaluation of a commercially available molybdate formulation and zinc oxide boluses in preventing hepatic copper accumulation and thus enzootic icterus in sheep. Journal of the South African Veterinary Association 72(4): 183-188

Van der Merwe D, Swan G E, Botha C J 2001 Use of ethnoveterinary medicinal plants in cattle by Setswana-speaking people in the Madikwe area of the North West province of South Africa. Journal of the South African Veterinary Association 72(4): 189-196

Book chapters

Van der Merwe D 2013 Freshwater cyanotoxins. . In Gupta R C, (ed.) Biomarkers in Toxicology. Elsevier/Academic Press, New York, pp. 539-548.

Gehring R, Van der Merwe D 2013 Toxicokinetic-Toxicodynamic modeling. In Gupta R C, (ed.) Biomarkers in Toxicology. Elsevier/Academic Press, New York, pp. 149-156.

Van der Merwe D, Buur JL, Gehring R 2012 Toxicokinetics. In: Gupta R C, (ed.) Veterinary Toxicology: Basic & Clinical Principles 2nd edition. Elsevier/Academic Press, New York, pp. 37-47.

Pickrell JA, Van der Merwe D 2012 Respiratory toxicosis. In: Gupta R C, (ed.) Veterinary Toxicology: Basic & Clinical Principles 2nd edition. Elsevier/Academic Press, New York, pp. 223-234

Van der Merwe D, Pickrell JA 2021 Nanomaterials toxicity. In: Gupta R C, (ed.) Veterinary Toxicology: Basic & Clinical Principles 2nd edition. Elsevier/Academic Press, New York, pp. 383-390.

Pickrell JA, Van der Merwe D, Erickson LE, Dhakal K, Dhakal M, Klabunde KJ, Sorensen C 2010 Comparative pulmonary toxicity of metal oxide nanoparticles. In: Nanoscale materials in chemistry. Larry E. Erickson, Ranjit T. Koodali, Ryan M. Richards (eds), ACS Books, Washington, D.C., ACS Symposium Series Volume 1045, pp. 225-233

Van der Merwe D 2009 Chapter 145: Poisons of plant origin. In: General and Applied Toxcology (3rd ed), Bryan Ballantyne, Timothy C. Marrs, Tore Syversen (eds.), Wiley, Hoboken, NJ, Volume 6, pp. 3449-3466.

Gehring R, Van der Merwe D 2008 Drug interactions. In: Haskell SSR (ed.) Five Minute Veterinary Consult, Rruminant. Wiley-Blackwell Publishing, Aimes, Iowa, 310-311

Gehring R, Van der Merwe D 2008 Drug hypersensitivity. In: Haskell SSR (ed.) Five Minute Veterinary Consult, Rruminant, Supplementary Material. Wiley-Blackwell Publishing, Aimes, Iowa, 176

Gehring R, Van der Merwe D 2008 Prudent use of antimicrobials. In: Haskell SSR (ed.) Five Minute Veterinary Consult, Rruminant, Supplementary Material. Wiley-Blackwell Publishing, Aimes, Iowa, 327-328

Van der Merwe D, Buur J L, Riviere J E 2007 Physiologically Based Pharmacokinetic Modeling. In: Gupta R C, (ed.) Veterinary Toxicology: Basic & Clinical Principles. Elsevier/Academic Press, New York, 42-50

Scientific meeting abstracts

Mahdi AJ, Van der Merwe D. The trends of hazardous substances exposures in dogs and cats reported to the Kansas State Veterinary Diagnostic Laboratory 2009-2013. American Association of Veterinary Laboratory Diagnosticians Annual Meeting, San Diego, California, October 17-23, 2013

Van der Merwe D, Price KP. Small unmanned aircraft-based remote sensing of harmful algal blooms. American Academy of Veterinary and Comparative Toxicology Annual Meeting, San Diego, California, October 18, 2013

Van der Merwe D. Buckeye poisoning. . American Academy of Veterinary and Comparative Toxicology Annual Meeting, San Diego, California, October 18, 2013

Van der Merwe D, Price KP. Using sUAS for high resolution characterization of harmful algal blooms. Kansas Unmanned Systems Conference, Manhattan, Kansas, October 14-16, 2013

Burchfield D, Price KP, Bryant J, Van der Merwe D, Wang H, An N, Armbrust R. Evaluating Bioenergy Potential of Eastern Redcedar Using a Small Unmanned Aircraft System (sUAS). Kansas Unmanned Systems Conference, Manhattan, Kansas, October 14-16, 2013

Attanayake CP, Hettiarachchi G, Van der Merwe D, Pierzynski GM. Transfer of Polycyclic Aromatic Hydrocarbons From Urban Soils to Humans Via Dermal Absorption. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America International Annual Meetings, Tampa, Florida, November 3-6, 2013

Remotely piloted aircraft systems and high resolution color infrared imagery for assessing herbicide drift and crop conditions. D Peterson, D van der Merwe, KP Price, D Burchfield, C Minihan. North Central Weed Science Society Annual Meeting, St. Louis, MS, December 10-13, 2012.

Selenium toxicosis in a herd of pigs. A.G. Cino-Ozuna, P.S. Malhi, S.C. Henry, L. Tokac, D. van der Merwe, and K.M. Almes, American College of Veterinary Pathologists Annual Meeting, Seattle, WA, December 1-5, 2012.

Small unmanned aircraft systems in agriculture. Kevin Price, Deon van der Merwe, The Commercial & Civil sUAS Conference, Wichita, KS, June 12, 2012.

Epidemiology of human illnesses and animal deaths associated with harmful algal blooms – Kansas, 2011. Ingrid Garrison, Tom Langer, Janet Neff, Henri Menager, Jamie DeMent, Patricia Hanes-Lieber, Edward Carney, Deon van der Merwe, Council of State and Terrirorial Epidemiologists 2012 Annual Conference, Omaha, NE, June 3-7, 2012

Using remotely-sensed measurements to map Eastern redcedar (Juniperus virginiana) and model its biomass productivity. David Burchfield, Kevin P. Price, Deon van der Merwe, Larry Biles, American Society for Photogrammetry and Remote Sensing, Central Region Annual Meeting, Eureka Springs, AR, May 18, 2012.

Soil arsenic and potential risk pathways of arsenic in urban garden soils. Hettiarachchi GM, Van der Merwe D, Datta S, Erickson L, Davis L, Martin S. The 8th International Phytotechnologies Conference, Portland, OR, 13-16 September, 2011.

Rapid confirmation, with minimal sample preparation, of calcium oxalate crystal deposition in renal tissue using ATR-FTIR spectroscopy. Van der Merwe D, Almes K, Blevins L. American Association of Veterinary Laboratory Diagnosticians 54th Annual Conference, Buffalo, NY, 28 September – 5 October, 2011.

Trace element composition of bovine milk in Kansas and Nebraska. Van der Merwe D, Gehring R. Geological Society of America Annual Meeting, Minneapolis, MN, 9-12 October, 2011.

Selenium speciation and mobilization in a controlled wetland system:Pariette Wetlands, UT. Mathew Crawford, Nicholas Allmendinger, Deon van der Merwe, Dustin Clark, Saugata Datta, Geological Society of America 2010 Annual Meeting, Denver, October 31-November 3, 2010.

A dermal absorption model based on successive partitioning through a non-homogenous stratum corneum lipid matrix. Deon van der Merwe, Phillip Schumm, Caterina Scoglio. 2010 Annual Meeting of the Society of Toxicology, Salt Lake City, March 7-11, 2010.

Selenium speciation and mobilization in a controlled wetland system:Pariette Wetlands, UT. Mathew Crawford, Nicholas Allmendinger, Deon van der Merwe, Dustin Clark, Saugata Datta, Geological Society of America 2010 Annual Meeting, Denver, October 31-November 3, 2010.

Petersen D, Burr D, Pohlman L, Galgut B, Van der Merwe D, Ganta C, Nietfeld J C 2009 Hepatic copper accumulation and liver cirrhosis in a dog. Paper presented at the 2009 ACVP/ASVCP Annual Meeting, Monterey, December 5-9, 2009.

Nietfeld J C, Van der Merwe D, Fisher D, Loughney K 2009 Copper Deficiency in Kansas Bison Paper presented at the 52nd Annual AAVLD/USAHA Meeting, San Diego, October 7-14, 2009.

Wisely S M, Van der Merwe D, Montelone B, Harkin K, Freeman L 2009 A call for collaborators: Developing a One Health Initiative across the LTER Network. Poster presented at the All Scientists Meeting, National Science Foundation – Long Term Ecological Research Program, Estes Park, September 13-17 2009

Jones M, Van der Merwe D 2009 Copper Toxicity in Small Ruminants. Proceedings of the Montana Veterinary Medical Association Summer Meeting, Billings, June 21-22, 2009.

Al-Bataineh M M, Van der Merwe D, Schultz B D, Coetzee J, Apley M, Gehring R 2009. Molecular and Functional Identification of Organic Anion Transporter Isoforms and Efflux Pump (P-gp) in Cultured Bovine Mammary Epithelial Cells (BME-UV). Poster presented at the AAVPT 16th Biennial Symposium, Rockville, June 14-17, 2009.

Nietfeld J C, Fisher D, Loughney K, Van der Merwe D 2009 Copper deficiency in a herd of Kansas bison. Paper presented at the K-State VMCE 71st Annual Conference for Veterinarians, June 7-10, 2009

Pickrell J A, Dhakal K, Erickson L E, Klabunde J K, Maghirang R G, Dhakal M, Van der Merwe D, Oehme F W 2008 Potential inhalation toxicity of nanomaterials. Paper presented at the American Institute of Chemical Engineers Annual Meeting, Philadelphia, November 16-20, 2008.

Van der Merwe D, Tawde S, Price KP 2008 Environmental effects on forage nitrate accumulation, and its association with climate change in the North American Great Plains. Paper presented at the 51st Annual Conference of the International Association for Vegetation Science, Stellenbosch, South Africa, September 7-12, 2008

Kershner T, Gehring R, Van der Merwe D, Beech C 2008 A spatial database of ethnoveterinary medicinal plant use in and around the Greater Limpopo Transfrontier Conservation Area. Poster presentated at the Society of Economic Botany’s 2008 Annual Meeting, Durham, USA, June 1-5, 2008

Tawde S, Van der Merwe D 2008 Nitrate toxicity risk assessment: from field sampling to remote sensing and beyond. Poster presentated at the Society of Toxicology’s 47th Annual Meeting, Seattle, USA, March 16-20, 2008

Van der Merwe D 2007 Correlations between normalized difference vegetation index data patterns and hazardous nitrate accumulation in forage plants. Poster presented at the AAVLD 50th Annual Conference, Reno, USA, October 18-23, 2007

Van der Merwe D, Wellman L, Gehring R 2007 Effective tortuosity applied to inter-species scaling of parathion dermal absorption in bovine and rat skin. Poster presentated at the Society of Toxicology’s 46th Annual Meeting, Charlotte, USA, March 25-29, 2007

Van der Merwe D, Brooks JD, Gehring R, Baynes RE, Monteiro-Riviere NA, Riviere JE 2006 A physiologically based pharmacokinetic model of parathion dermal absorption. Poster presentated at the Society of Toxicology’s 45th Annual Meeting, San Diego, USA, March 5-9, 2006

Van der Merwe D, Gehring R, Baynes RE, Monteiro-Riviere NA, Riviere JE 2005 A physiologically based pharmacokinetic model of fenthion absorption through porcine skin in a flow-through cell. Presented at: 14th Bienniel Symposium of the American Academy of Veterinary Pharmacology and Therapeutics, Washington DC, USA, May 16-18, 2005

Gehring R, Van der Merwe D, Baynes RE, Riviere JE 2005 A mechanistic mathematical model to predict milk concentrations of parenterally administered drugs. Presented at: 14th Bienniel Symposium of the American Academy of Veterinary Pharmacology and Therapeutics, Washington DC, USA, May 16-18, 2005

Van der Merwe D, Riviere JE 2004 A comparative investigation of the effects of water, ethanol and water/ethanol mixtures on chemical partitioning into porcine stratum corneum and permeability in porcine skin. Poster presentated at the Society of Toxicology’s 43rd Annual Meeting, Baltimore, USA, March 21-25, 2004

Van der Merwe D 2002 Ethnoveterinary medicine in southern Africa: key concepts and implications. Paper presented at the Indigenous Plant Use Forum, George, South Africa, July 9-12, 2002

Katsoulis LC, Gehring R, Van der Merwe D 2002 The effect of Sclerocarya birrea aqueous bark extracts on rat intestinal contractility. Poster presented at the Indigenous Plant Use Forum, George, South Africa, July 9-12, 2002

Van der Merwe D 1999 Ethnoveterinary plant use in cattle by Setswana-speaking people in the North West Province of South Africa. Poster presented at the Second International Conference on Pharmaceutical and Pharmacological Sciences (South Africa), Cape Town, South Africa, October 3-6, 1999

Extension Publications

Ecstacy poisoning in a dog. Kenneth Harkin, Deon van der Merwe, Kansas Veterinary Quarterly, Summer 2012, 15(1):3-4.

Identification and management of blue-green algae in farm ponds. Deon van der Merwe, Carol Blocksome, Larry Hollis, KSRE June 2012.

How to test your pond for blue-green algae. KSREVideos: http://youtu.be/ZRNWzFwKKjE

Blue-green algae. Interview with Dr. Dan Thompson, “Doc Talk”

http://www.agaminkansas.com/doc_talk_09052011.php
Nitrate poisoning. Interview with Dr. Dan Thompson, “Doc Talk” http://www.agaminkansas.com/doc_talk_05092011.php

Hollis LC, Van der Merwe D 2010 Kochia toxicity. K-State Research and Extension Bulletin

Hollis LC, Van der Merwe D 2010 Hairy vetch toxicity. K-State Research and Extension Bullletin

Algae blooms a water hazard for dogs in Kansas. Interview with Christine Metz, ABC Channel 49 News (http://www.ktka.com/news/2010/sep/06/algae-blooms-water-hazard-dogs-kansas/)

Poison hemlock poisoning in cattle. Interview with Dr. Dan Thompson, “Doc Talk” (http://www.agaminkansas.com/doc_talk_07052010.php)

Zearalinone poisoning in swine. Interview with Dr. Dan Thompson, “Doc Talk” (http://www.agaminkansas.com/doc_talk_10042010.php)

(http://www.agaminkansas.com/doc_talk_10042010.php) DeBey B, Van der Merwe D 2008 Blue-green algae toxicosis in dogs in Kansas. Kansas Veterinary Quarterly for the Practicing Veterinarian, (In press)

Jones M, Van der Merwe D 2008 Copper toxicity is on the rise in Kansas and Nebraska. Kansas Veterinary Quarterly for the Practicing Veterinarian, Fall 2008, 11(4):2-3

Pickrell JA, Nietfeld J, Kuroki K, Blevins L, Van der Merwe D, Oehme FW 2007 Case study: Poor quality hay leads to nitrate intoxication. Kansas Veterinary Quarterly for the Practicing Veterinarian, Winter 2007, 11(1):6-7

K-State Media Relations Podcast: Toxic hazards for pets (http://www.ksu.edu/media/audio/podcastindex.html)

K-State Media Relations News Release: K-state animal poison control hotline available 8 a.m. to 5 p.m. regular business days. Prepared by Shelby Haag December 11, 2007 (http://www.ksu.edu/media/newsreleases/dec07/poisonhotline121107.html)