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   Assistant Professor of Toxicology Phone: 785–532 4333 Fax: 785–532 4481 Email: dmerwe@vet.ksu.edu

Research

My primary interests as a veterinarian and a comparative biomedical scientist are in the use of quantitative models in toxicology and in veterinary botany.

I do research on the absorption of chemicals into the body following skin exposure. I am particularly interested in the extrapolation of data obtained under laboratory conditions, to the highly variable conditions typically encountered in real-world human exposures to chemicals. It includes the extrapolation of data between species, so that we may make better use of data obtained from laboratory animals such as rats. This work will reduce the numbers of experimental animals needed to assess the risks of chemical exposure and provide more accurate assessments of the risks posed by chemicals in the environment associated with agricultural or industrial activities and accidental or malicious release of chemicals into the environment.

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. I use geographic information systems (GIS) and remotely sensed data derived from satellites to build models of the conditions under which poisonings typically occur. These models may help us to predict when and where poisonings can be expected and help us to take precautions to limit losses.

Teaching

My teaching responsibilities include an Environmental Toxicology course for graduate students and Clinical Toxicology for veterinary students in the professional curriculum.
 

Service

I participate in providing toxicological diagnostic services at the KSU Veterinary Diagnostic Laboratory. I also provide toxicological information and consultations as a service to veterinary colleagues and the general public.

 

Selected Publications

Van der Merwe D, Du Plessis L 2007 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 (In Press)

Spickett 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 L J, Van der Merwe D, Eloff J N 2006 In vitro anthelmintic, antibacterial and cytotoxic effects of extracts from plants used in South African ethnoveterinary medicine. The Veterinary Journal (In Press)

Luseba D, Van der Merwe D 2006 Ethnoveterinary medicine practices among Tsonga speaking people of South Africa. Onderstepoort Journal of Veterinary Research 73(2):115-22.

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.

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 Meta-analysis and clustering of ampicillin trihydrate pharmacokinetic studies in cattle using multi-variate analysis. 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