Horak, Katherine

Dr. Katherine Horak

Dr. Katherine Horak  

Katherine Horak is a pharmacologist and toxicologist at the National Wildlife Research Center.

NWRC Research Project: Analytical Chemistry

Current Research

Dr. Horak is currently involved in the development of physiologically-based pharmacokinetic models of anticoagulant rodenticides warfarin and diphacinone for rats and quail. These models will generate approximations of rodenticide residues in various tissues and, therefore, provide a means to estimate the sensitivity of non-target species to rodenticide residues.


  • Ph.D., University of Arizona, Pharmacology and Toxicology, "CD4+ lymphocyte regulation of vascular and cardiac extracellular matrix structure and function"
  • B.S., Northern Arizona University, Mathematics
  • B.S., Northern Arizona University, Biology

Contact Information

Recent Publications


Patton, T.G., S.L. Blamer, and K.E. Horak. 2016. Detecting methemoglobinemia in animals with a drop of blood.  Plos one 11(12):e0167942.  doi:10.1371/journal.pone.0167942


Rattner, B.A., K.E. Horak, R.S. Lazarus, S.L. Schultz, S. Knowles, B.G. Abbo, and S.F. Volker. 2015.Toxicity reference values for chlorophacinone and their application for assessing anticoagulant rodenticide risk to raptors. Ecotoxicology 24:720-734.  doi: 10.1007/s10646-015-1418-8.

Horak, K.E., S.F. Volker, and C.M. Campton. 2015. Increased diphacinone and chlorophacinone metabolism in previously exposed wild caught voles, Microtus californicus. Crop Protection 7:35-39.  doi: 10.1016/j.cropro.2015.08.011


Rattner, B.A., R.S. Lazarus, S.L. Schultz, K.E. Horak, B.G. Abbo, and S.F. Volker. 2014. Development of dietary-based toxicity reference values to assess the risk of chlorophacinone to non-target raptorial birds. Proceedings of the 26th Vertebrate Pest Conference 26:347-352.  

Horak, K., R. Chipman, L. Murphy, and J. Johnston. 2014. Environmental contaminant concentrations in Canada Goose (Branta canadensis) muscle: Probabilistic risk assessment for human consumers. Journal of Food Protection 77(9):1634-1641. doi: 10.4315/0362-028X.JFP-13-364.

Rattner, B.A., K.E. Horak, R.S. Lazarus, D.A. Goldade, and J.J. Johnston. 2014. Toxicokinetics and coagulopathy threshold of the rodenticide diphacinone in Eastern screech-owls (Megascops asio). Environmental Toxicology and Chemistry 33(1): 74-81. doi: 10.1002/etc.2390.


Rattner B.A., Horak K.E., Warner S.E., Day D.D., Meteyer C.U., Volker S.F., Eisemann J.D., Johnston J.J. 2011. Acute Toxicity, Histopathology, and Coagulopathy in American Kestrels (Falco Sparverius) following administration of the Rodenticide Diphacinone. Environmental Toxicology and Chemistry 30:1213-1222. DOI: 10.1002/etc.490.


Horak, K. E., C. R. Wermager, and T. M. Primus. 2010. The use of liver microsome in-vitro methods to study toxicant metabolism and predict species efficacy. Proceedings of the Vertebrate Pest Conference 24:195-198. 324K

Rattner B.A., Horak K.E., Lazarus R.S., Eisenreich K.M., Meteyer C.U., Volker S.F., Campton C.M., Eisemann J.D., Johnston J.J. 2012. Assessment of toxicity and potential risk of the anticoagulant rodenticide diphacinone using Eastern screech-owls (Megascops asio). Ecotoxicology 21:832-846.

Rattner B.A., Horak K.E., Warner S.E., Day D.D., Johnston J.J. 2010. Comparative toxicity of diphacinone to northern bobwhite ( Colinus virginianus ) and American kestrels ( Falco sparverius ). Proceedings of the Vertebrate Pest Conference 24:146-152.

Rattner B.A., Horak K.E., Warner S.E., Johnston J.J. 2010. Acute toxicity of diphacinone in Northern bobwhite: Effects on survival and blood clotting. Ecotoxicology and Environmental Safety 73:1159-1164.


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