Carnivore Diseases

Whether a top predator like the grey wolf, or a carrion feeder like the opossum, carnivores play a key role in the ecosystem.  They can also play an important role in the maintenance and spread of many diseases – some of which may be of concern to other wildlife, domestic animals, or even humans. 

Concern over emerging vector-borne diseases has recently increased for both aninal and human health.  In the US, vector-borne diseases affecting domestic dogs are primarily Lyme disease, anaplasmosis, ehrlichiosis, and heartworm. Lyme disease and anaplasmosis are bacterial diseases transmitted by deer ticks, while ehrlichiosis is transmitted by the brown dog tick.  In contrast, heartworm parasites can be transmitte by several species of mosquitoes.

Our lab is currently researching the prevalence and distribution of vector-borne diseases affecting Wisconsin’s wolf population.  Research objectives are: 1) To determine the temporal prevalence and geographic distribution of gray wolf exposure to these four vector-borne diseases in Wisconsin between 1985 and 2011 and 2) Trends in the prevalence of these diseases in wolves will be compared to domestic dogs to evaluate if their infection patterns correspond.





The Samuel lab has also conducted studies screening for a wide range of pathogens in mesocarnivores and other mammals.







Michael D. Samuel, PhD
(Lab Leader)


Rocio Jara, DVM
(M.S. program)


Cherie Nolden
(Former Student)



Docherty, D.E., M.D. Samuel, K.F. Egstad, K.M. Griffin, C.A. Nolden, L. Karwal, and H.S. IP. 2009. Changes in West Nile seroprevalence and antibody titers among Wisconsin mesopredators 2003-2006. American Journal of Tropical Medicine and Hygiene 81:177-179

Joly, D.O., D.M. Heisery, M.D. Samuel, C.A. Ribic, N. Thomas, S.D. Wright, and I.E. Wright. 2009. Estimating cause-specific mortality rates using data derived from recovered carcasses. Journal of Wildlife Diseases 45:122-127

Hill, D. E., M. D. Samuel, C. A. Nolden, N. Sundar, D. S. Zarlenga, and J. P. Dubey. 2008. Tichinella murrelli in scavenging mammals from south-central Wisconsin, USA. Journal of Wildlife Diseases 44: 629-635.

Sundar, N., I. M. Asmundsson, N. J. Thomas, M. D. Samuel, J. P. Dubey, and B .M. Rosenthal. 2008. Modest genetic differentiation among North American populations of Sarcocystis neurona may reflect expansion in its geographic range

Dubey, J. P., N. Sundar, C. A. Nolden, M. D.Samuel, G. V. Velmurugan, L. A. Bandini, O. C. H. Kwok, B. Bodenstein, and C. Su. 2007. Characterization of Toxoplasma gondii from raccoons (Procyon lotor), coyotes (Canis latrans), and stripped skunks (Mephitis mephitis) in Wisconsin identified several atypical genotypes.  Journal of Parasitology 93:1524-1527.

Anderson, J. L. et al. 2007. Mycobacterium avium subsp. paratuberculosis in Scavenging Mammals in Wisconsin. Journal of Wildlife Diseases, 43(2), pp. 302-308.

Docherty, D.E., M.D. Samuel, C.A. Nolden, K.E. Egstad, and K.M. Griffin. 2006. West Nile Virus Antibody Prevalence in Medium-sized mammals in southern Wisconsin. Emerging Infectious Diseases 12:1978-1980.