Liver Flukes (Fascioloides magna) in White-Tailed Deer ......Life cycle begins as embryonated eggs...
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Liver Flukes (Fascioloides magna) in White-Tailed Deer During Hunting Season 2019 Madeline Abbatacola and Kelsie Hayes, Dr. Shelli Dubay and Ross McLean Life cycle begins as embryonated eggs pass through feces and land in wetlands where they encounter snail intermediate hosts. Development inside the snail lasts 40-58 days and includes a sporocyst and cercarial stage (Haider et. al. 2012). White-tailed deer (Odocoileus virginianus) ingest infected snails and are then infected (Dunkel et. al. 1996). Once inside the deer, the migrating larvae cause lesions in the liver while the adult stage stimulate fibrous pseudocysts to form which often leads to inflammation, liver malfunction, and death (Nagy et. al. 2018). Generally, a liver fluke infection is not lethal, but the flukes are able to continue movement through domestic animals causing fatal destruction of liver tissue (Wobeser and Schumann 2014). The presence of dead end hosts often exerts a dilution effect of parasites and may reduce the prevalence in a multi-host system (Pruvot et. al. 2016). Negative association between the cattle density and the occurrence of liver flukes in elk (Cervus elaphus) suggests that dead end hosts consume and remove infective stage parasites which reduce them from the landscape (Pruvot et. al. 2016). Introduction Hypothesis Liver flukes (Fascioloides magna) will be more prevalent from white-tailed deer (Odocoileus virginianus) harvested in counties within the forest zones than in the farmland zones because intermediate hosts are more prevalent in forests. Methods • Deer livers were collected from the start of archery deer season on September 14th until the closing of the traditional 9-day gun deer season on December 1st, for a total duration of 79 days for collection. • Livers were obtained through the donation of hunter harvested deer; which entailed a statewide range. • We recorded date of harvest, county of harvest, sex, location of harvest (wetlands, etc.), and general body condition of the individual (how was condition assessed?). • Livers were dissected within three days or frozen prior to dissection. • Liver dissection consisted of cross-sectioning for multiple examination opportunities for liver flukes. If found, the number of flukes was recorded, and the damage was assessed. • Livers were processed and dissected in a lab at the University of Wisconsin- Stevens Point following proper lab protocol and disposal methods. • We performed a t-test to determine if the number of flukes per host differed by harvest location, Results We dissected 61 livers vut internsity (number of flukes per host) did not differ with habitat where the deer was harvested (p-value of 0.3547, Fig. 1) • No statistical difference for infection intensity between the prevalence in forested and farmland zones. • More samples collected from the forest zone would be beneficial to even the distribution of livers for the hypothesis. Deer home ranges are large (give data) and so the harvest location might not reflect area where deer might acquire infection. • Future studies could compare age class and fluke prevalence to determine if deer acquire more over time. Discussion Figure 1. The highest infection intensity was an eight-point male harvested from a wetland with thirty-three flukes. The highest infection intensity female had eight flukes and was harvested from the same property as the highest male. (left) Figure 2. The study collected from a total of 22 counties out of Wisconsin's 72. The graph represents the number of livers from each county. Highlighted are the top 3 counties with the most livers coming from Waupaca county then Iowa and tied for third were Columbia and Rusk counties. 1. Department of Natural Resources. Jun. 2019. Protecting Wisconsin’s biodiversity. https://dnr.wi.gov/topic/EndangeredResources/biodiversity.html 2. Dunkel, A. M., Rognlie, M. C., Johnson, G. R., and S.E Knapp. 1996. Distribution of potential intermediate hosts for Fasciola hepatica and Fascioloides magna in Montana, USA. Veterinary Parasitology 62: 63–70. 3. Haider, M., C. Hörweg, K. Liesinger, H. Sattmann, and J. Walochnik. Jul 2012. Recovery of Fascioloides Magna (Digenea) population in spite of treatment programme? Screening of Galba Truncatula (Gastropoda, Lymnaeidae) from lower Austria. Veterinary Parasitology 187: 445-51. 4. Nagy, E., I. Jócsák, A. Csivincsik, A. Zsolnai, T. Halász, A. Nyúl, Z. Plucsinszki, T. Simon, Tamás, S. Szabó, J. Turbók, C. Nemes, L. Sugár, and G. Nagy. 2018. Establishment of Fascioloides magna in a new region of Hungary: case report." Parasitology Research 117:: 3683-36687. 5. Pruvot, M., M. Lejeune, S. Kutz, W. Hutchins, M. Musiani, A. Massolo, and K. Orsel. Jul. 2016. Better alone or in ill company: the effect of migration and inter-species commingling on fascioloides magna infection in elk. PloS One 11:e0159319 6. US Climate Data. 2019. Wisconsin climate. https://www.usclimatedata.com/climate/wisconsin/united-states/3219 7. Wobeser, B.K. and F. Schumann. Nov. 2014. Fascioloides magna infection causing fatal pulmonary hemorrhage in a steer. The Canadian Veterinary Journal 55:1093-1095. 8. Perry, C.H. V.A. Everson, I.K. Brown, J. CummingsCarlson, S.E. Dahir, E.A. Jepson, J. Kovach, M.D. LaBissoniere, T.R. Mace, E.A. Padley, R.B. Rideout, B.J. Butler, S.J. Crocker, G.C. Liknes, R.S. Morin, M.D. Nelson, B.T. Wilson, and C.W. Woodall. 2008. Wisconsin Forests. United States Forest Service. References
Transcript of Liver Flukes (Fascioloides magna) in White-Tailed Deer ......Life cycle begins as embryonated eggs...
Liver Flukes (Fascioloides magna) in White-Tailed Deer During Hunting Season 2019
Madeline Abbatacola and Kelsie Hayes, Dr. Shelli Dubay and Ross McLean
The large American liver fluke, Fascioloides magna, is common in wild and domestic ruminants throughout North America. The Life cycle begins as embryonated eggs pass through feces and land in wetlands where they encounter snail intermediate hosts. Development inside the snail lasts 40-58 days and includes a sporocyst and cercarial stage (Haider et. al. 2012). White-tailed deer (Odocoileus virginianus) ingest infected snails and are then infected (Dunkel et. al. 1996). Once inside the deer, the migrating larvae cause lesions in the liver while the adult stage stimulate fibrous pseudocysts to form which often leads to inflammation, liver malfunction, and death (Nagy et. al. 2018). Generally, a liver fluke infection is not lethal, but the flukes are able to continue movement through domestic animals causing fatal destruction of liver tissue (Wobeser and Schumann 2014). The presence of dead end hosts often exerts a dilution effect of parasites and may reduce the prevalence in a multi-host system (Pruvot et. al. 2016). Negative association between the cattle density and the occurrence of liver flukes in elk (Cervus elaphus) suggests that dead end hosts consume and remove infective stage parasites which reduce them from the landscape (Pruvot et. al. 2016).
Introduction
HypothesisLiver flukes (Fascioloides magna) will be more prevalent from white-tailed deer (Odocoileus virginianus) harvested in counties within the forest zones than in the farmland zones because intermediate hosts are more prevalent in forests.
Methods• Deer livers were collected from the start of archery deer season
on September 14th until the closing of the traditional 9-day gun deer season on December 1st, for a total duration of 79 days for collection.
• Livers were obtained through the donation of hunter harvested deer; which entailed a statewide range.
• We recorded date of harvest, county of harvest, sex, location of harvest (wetlands, etc.), and general body condition of the individual (how was condition assessed?).
• Livers were dissected within three days or frozen prior to dissection.
• Liver dissection consisted of cross-sectioning for multiple examination opportunities for liver flukes. If found, the number of flukes was recorded, and the damage was assessed.
• Livers were processed and dissected in a lab at the University of Wisconsin- Stevens Point following proper lab protocol and disposal methods.
• We performed a t-test to determine if the number of flukes per host differed by harvest location,
ResultsWe dissected 61 livers vut internsity (number of flukes per host) did not differ with habitat where the deer was harvested (p-value of 0.3547, Fig. 1)
• No statistical difference for infection intensity between the prevalence in forested and farmland zones.
• More samples collected from the forest zone would be beneficial to even the distribution of livers for the hypothesis. Deer home ranges are large (give data) and so the harvest location might not reflect area where deer might acquire infection.
• Future studies could compare age class and fluke prevalence to determine if deer acquire more over time.
Discussion
Figure 1. The highest infection intensity was an eight-point male harvested from a wetland with thirty-three flukes. The highest infection intensity female had eight flukes and was harvested from the same property as the highest male.
(left) Figure 2. The study collected from a total of 22 counties out of Wisconsin's 72. The graph represents the number of livers from each county. Highlighted are the top 3 counties with the most livers coming from Waupaca county then Iowa and tied for third were Columbia and Rusk counties.
1. Department of Natural Resources. Jun. 2019. Protecting Wisconsin’s biodiversity. https://dnr.wi.gov/topic/EndangeredResources/biodiversity.html2. Dunkel, A. M., Rognlie, M. C., Johnson, G. R., and S.E Knapp. 1996. Distribution of potential intermediate hosts for Fasciola hepatica and Fascioloides magna in Montana, USA. Veterinary Parasitology 62: 63–70.3. Haider, M., C. Hörweg, K. Liesinger, H. Sattmann, and J. Walochnik. Jul 2012. Recovery of Fascioloides Magna (Digenea) population in spite of treatment programme? Screening of Galba Truncatula (Gastropoda, Lymnaeidae) from lower Austria. Veterinary Parasitology 187: 445-51.4. Nagy, E., I. Jócsák, A. Csivincsik, A. Zsolnai, T. Halász, A. Nyúl, Z. Plucsinszki, T. Simon, Tamás, S. Szabó, J. Turbók, C. Nemes, L. Sugár, and G. Nagy. 2018. Establishment of Fascioloides magna in a new region of Hungary: case report." Parasitology Research 117:: 3683-36687.5. Pruvot, M., M. Lejeune, S. Kutz, W. Hutchins, M. Musiani, A. Massolo, and K. Orsel. Jul. 2016. Better alone or in ill company: the effect of migration and inter-species commingling on fascioloides magna infection in elk. PloS One 11:e01593196. US Climate Data. 2019. Wisconsin climate. https://www.usclimatedata.com/climate/wisconsin/united-states/32197. Wobeser, B.K. and F. Schumann. Nov. 2014. Fascioloides magna infection causing fatal pulmonary hemorrhage in a steer. The Canadian Veterinary Journal 55:1093-1095.8. Perry, C.H. V.A. Everson, I.K. Brown, J. CummingsCarlson, S.E. Dahir, E.A. Jepson, J. Kovach, M.D. LaBissoniere, T.R. Mace, E.A. Padley, R.B. Rideout, B.J. Butler, S.J. Crocker, G.C. Liknes, R.S. Morin, M.D. Nelson, B.T. Wilson, and C.W. Woodall. 2008. Wisconsin Forests. United States Forest Service.
References
