Katherine H. Petersson

  • Professor and Chair
  • Animal/Veterinary Science, Sustainable Agriculture/Food Systems
  • Phone: 401.874.2951
  • Email: kpetersson@uri.edu
  • Office Location: CBLS, Rm 177
  • Website


Gastrointestinal nematodes (GIN), such as Haemonchus contortus, are recognized as serious constraint to the sustainable production of food animals worldwide, particularly small ruminants such as sheep and goats. These GIN parasites, particularly H. contortus, the most pathogenic of the GIN, cause poor growth, anemia and death in severe infections. Young animals are the most susceptible due to their immature immune function but older animals, under the stress of pregnancy and lactation, can be similarly susceptible to severe infections. The development of widespread GIN resistance to the few commercially available dewormers on the market has made the identification of alternative control methods for GIN of paramount importance.

Dr. Petersson’s research interests in GIN infections of small ruminants are primarily focused on the interaction between nutrition, production, and immune competence as well as the interaction between the host and parasite with the goal being the development of innovative management strategies that will not only improve the health and wellbeing of the small ruminants but the financial viability of the stakeholders, the small ruminant producers.

Areas of focus:

  1. Characterization of the nutritional and immune factors influencing the host:GIN parasite interaction.
  2. Anti-parasitic efficacy of plants and forages containing condensed tannins and other plant secondary compounds.
  3. Bt crystal proteins for control of GIN parasites in livestock.


  • Ph.D., Animal Science, 1990, Cornell University
  • M.S., Animal Science, 1986, Cornell University
  • B.S., Animal Science, 1982, Texas A&M University

Selected Publications

Sanders, J., Xie, Y., Gazzola, D., Li, H., Abraham, A., Flanagan, K., Rus, F., Miller, M., Huc, Y., Guynn, S., Draper, A., Vakalapudi, S., Petersson, K., Zarlenga, D., Li, R., Urban Jr., J., Ostroff, G., Zajac, A., Aroian, R. 2020. A New Paraprobiotic-based Treatment for Control of Haemonchus contortus in Sheep. International Journal of Parasitology: Drugs and Drug Resistance 14:230-236.

Lonngren, K., Barone, C., Zajac, A., Brown, R., Reed, J, Krueger, C., Petersson, K. (2020) Effect of birdsfoot trefoil cultivars on exsheathment of Haemonchus contortus in fistulated sheep. Veterinary Parasitology 287:109271.

Barone, C.D., Zajac, A.M., Ferguson, S.M., Brown, R.N., Reed, J.D., Krueger, C.G. and
Petersson, K.H. 2019. In vitro screening of 51 birdsfoot trefoil (Lotus corniculatus L.;
Fabaceae) strains for anti-parasitic effects against Haemonchus contortus. Parasitology 146:828- 836. https://doi.org/10.1017/S0031182018002214.

Barone, C.D., Zajac, A.M., Manzi-Smith, L.A., Howell, A.B., Reed, J.D., Krueger, C.G., Petersson, K.H. 2018.Anthelmintic efficacy of cranberry vine extracts on ovine Haemonchus contortus. Vet Parasitol. https://doi.org/10.1016/j.vetpar.2018.02.016

De Wolf, B.M., Zajac, A.M., Hoffer, K.A., Sartini, B.L., Bowdridge, S., LaRoith, T., Petersson, K.H. 2014. The effect of vitamin E supplementation on an experimental Haemonchus contortus infection in lambs. Vet Parasitol. 205:140-149.

Anugu, S.A., Petersson-Wolfe, C.S., Combs, G.F., Jr., Petersson, K.H. 2013. Effect of vitamin E on the immune system of ewes during late pregnancy and lactation. Small Ruminant Research 111:83-89.

Petersson, K. H., Connor, L., Petersson-Wolfe, C.S., Rego, K. A. 2011 Evaluation of confirmatory stains used for direct microscopic somatic cell counting of sheep milk. Journal of Dairy Science 94:1908-1912.

MacGlaflin, C., Zajac, A., Rego, K., Petersson, K. 2011. Effect of vitamin E supplementation on naturally acquired parasitic infection in lambs. Vet. Parasitology 175:300-305.