Veterinary Medicine Commons^™

Hawaii As A Microcosm: Advancing The Science And Practice Of Managing Introduced And Invasive Species, Liba Pejchar, Christopher A. Lepczyk, Jean E. Fantle-Lepczyk, Steven C. Hess, M. Tracy Johnson, Christina R. Leopold, Michael Marchetti, Katherine M. Mcclure, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species are a leading driver of global change, with consequences for biodiversity and society. Because of extraordinary rates of endemism, introduction, and extinction, Hawaii offers a rich platform for exploring the cross-disciplinary challenges of managing invasive species in a dynamic world. We highlight key successes and shortcomings to share lessons learned and inspire innovation and action in and beyond the archipelago. We then discuss thematic challenges and opportunities of broad relevance to invaded ecosystems and human communities. Important research needs and possible actions include eradicating mammals from mainland island sanctuaries, assessing hidden threats from poorly known introduced species, harnessing …

Deciphering Interactions Between White-Tailed Deer And Approaching Vehicle, Morgan Pfeiffer, Raymond B. Iglay, Thomas W. Seamans, Bradley F. Blackwell, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Deer-vehicle collisions are a major transportation hazard, but factors affecting deer escape decision-making in response to vehicle approach remain poorly characterized. We made opportunistic observations of deer response to vehicle approach during daylight hours on a restricted- access facility in Ohio, USA (vehicle speeds were ≤64 km/h). We hypothesized that animal proximity to the road, group size, vehicle approach, and ambient conditions would affect perceived risk by white-tailed deer (Odocoileus virginianus) to vehicle approach, as measured by flight-initiation distance (FID). We constructed a priori models for FID, as well as road-crossing behavior. Deer responses were variable and did not demonstrate …

Evaluating Moose Alces Alces Population Response To Infestation Level Of Winter Ticks Dermacentor Albipictus, Daniel D. Ellingwood, Peter J. Pekins, Henry Jones, Anthony R. Musante

United States Department of Agriculture Wildlife Services: Staff Publications

Many wildlife populations are experiencing a variety of environmental pressures due to the direct and indirect consequences of a changing climate. In the northeast, USA, moose Alces alces are declining in large part because of the increasing parasitism by winter tick Dermacentor albipictus, facilitated by high host density and optimal environmental conditions. To test this hypothesis, and better understand the influence of this interaction on the stability of the regional population, we constructed a population viability model using data collected through comprehensive survival and productivity studies in 2002–2005 and 2014–2018 in northern New Hampshire. Years of heavy tick infestation (epizootics) …

Spillover Of Sars-Cov-2 Into Novel Wild Hosts In North America: A Conceptual Model For Perpetuation Of The Pathogen, Alan B. Franklin, Sarah N. Bevins

United States Department of Agriculture Wildlife Services: Staff Publications

There is evidence that the current outbreak of the novel coronavirus SARS-CoV-2, which causes COVID-19, is of animal origin. As with a number of zoonotic pathogens, there is a risk of spillover into novel hosts. Here, we propose a hypothesized conceptual model that illustrates the mechanism whereby the SARS-CoV-2 could spillover from infected humans to naive wildlife hosts in North America. This proposed model is premised on transmission of SARS-CoV-2 from human feces through municipal wastewater treatment plants into the natural aquatic environment where potential wildlife hosts become infected. We use the existing literature on human coronaviruses, including SARS CoV, …

Presence Of Dirofilaria Immitis In Mosquitoes In Southeastern Georgia, Angelica C. Tumminello

Honors College Theses

Canine heartworm disease is caused by the filarial nematode Dirofilaria immitis, which is transmitted by at least 25 known species of mosquito vectors. This study sought to understand which species of mosquitoes are present in Bulloch County, Georgia, and which species are transmitting canine heartworm disease. This study also investigated whether particular canine demographics correlated with a greater risk of heartworm disease. Surveillance of mosquitoes was conducted in known heartworm-positive canine locations using traditional gravid trapping and vacuum sampling. Mosquito samples were frozen until deemed inactive, then identified by species and sex. The mosquitoes were then either dissected under …

Public Perspectives And Media Reporting Of Wolf Reintroduction In Colorado, Rebecca Niemiec, Richard E.W. Berl, Mireille Gonzalez, Tara Teel, Cassiopeia Camara, Matthew Collins, Jonathan Salerno, Kevin Crooks, Courtney Schultz, Stewart Breck, Dana Hoag

United States Department of Agriculture Wildlife Services: Staff Publications

In the state of Colorado, a citizen ballot initiative to reintroduce gray wolves (Canis lupus) is eliciting polarization and conflict among multiple stakeholder and interest groups. Given this complex social landscape, we examined the social context surrounding wolf reintroduction in Colorado as of 2019. We used an online survey of 734 Coloradans representative in terms of age and gender, and we sampled from different regions across the state, to examine public beliefs and attitudes related to wolf reintroduction and various wolf management options. We also conducted a content analysis of media coverage on potential wolf reintroduction in 10 major daily …

Use Of Diatomaceous Earth And Copper Oxide Wire Particles To Control Gastrointestinal Nematodes In Lambs, Olivia Jones

Animal Science Undergraduate Honors Theses

Abstract

Anthelmintic resistance (AR) urges alternatives to control gastrointestinal nematodes (GIN). Copper oxide wire particles (COWP) are more efficacious when used with other dewormers and little is known on efficacy of diatomaceous earth (DE) to control gastrointestinal parasites. The objective was to examine the effects of DE and COWP on GIN control. Katahdin lambs (n = 32; ~150 d of age; 25.0 ± 1.8 kg) were randomly assigned to receive: 1) DE fed at an estimated 2% dry matter intake (with the assumption of moderate consumption of bermudagrass forage and provided supplement), 2) 1g COWP, 3) both 2% DE and …

Development And Diagnostic Application Of Monoclonal Antibodies Against Swine Acute Diarrhea Syndrome Coronavirus (Sads-Cov), Molly Kroeger

Schultz-Werth Award Papers

Swine Acute Diarrhea Syndrome Coronavirus (SADS-CoV) is a member of the Coronaviridae family. The virus is associated with severe small intestine inflammation and diarrhea in suckling piglets. In 2017, SADS-CoV was first detected and identified as the causative agent of a devasting swine disease outbreak in southern China. Routine monitoring and early detection of the source of infection is therefore integral to the prevention and control of a SADS-CoV outbreak in the United States. However, the United States does not currently have any diagnostic or surveillance tests to identify this emerging disease. To address these industry needs, we developed monoclonal …

Talking Trash In The Big Apple: Mitigating Bird Strikes Near The North Shore Marine Transfer Station, Stephan J. Beffre, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Anthropogenic activities that concentrate wildlife near airports increases the risk of wildlife–aircraft collisions. Placing waste management facilities, natural areas, golf courses, and other landscape features near airports have the potential to attract wildlife hazardous to aviation. We conducted a 3-year study (March 2013–February 2016) to determine if the implementation of a Wildlife Hazard Mitigation Program (WHMP) would influence the bird use of a waste transfer station located near LaGuardia Airport, New York City, New York, USA. We conducted wildlife surveys during 3 phases: (1) no mitigation program and no waste transfer station, (2) active mitigation and no waste transfer station, …

Collective Effect Of Landfills And Landscape Composition On Bird–Aircraft Collisions, Morgan Pfeiffer, Bradley F. Blackwell, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Ninety-three percent of all reported bird strikes occur below 1,067 m, which based on the typical approach and departure angles of aircraft is within 8–13 km of an airport. Concomitantly, the Federal Aviation Administration and the International Civil Aviation Organization recommend that any feature that would attract hazardous wildlife to the approach and departure airspace be restricted. Thus, preventing the establishment of wildlife attractants, such as municipal solid waste landfills (MSWLFs) within 8 km or 13 km extents (U.S. and international recommendations, respectively) of airports, has been recommended to mitigate the risk of bird–aircraft collisions (strikes). However, robust evidence linking …

Testing A Key Assumption Of Using Drones As Frightening Devices: Do Birds Perceive Drones As Risky?, Conor C. Egan, Bradley Blackwell, Esteban Fernández-Juricic, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife managers have recently suggested the use of unmanned aircraft systems or drones as nonlethal hazing tools to deter birds from areas of human-wildlife conflict. However, it remains unclear if birds perceive common drone platforms as threatening. Based on field studies assessing behavioral and physiological responses, it is generally assumed that birds perceive less risk from drones than from predators. However, studies controlling for multiple confounding effects have not been conducted. Our goal was to establish the degree to which the perception of risk by birds would vary between common drone platforms relative to a predator model when flown at …

Factors Affecting Bait Site Visitation: Area Of Influence Of Baits, Jacquelyn E. Mcrae, Peter E. Schlichting, Nathan P. Snow, Amy J. Davis, Kurt C. Vercautern, John C. Kilgo, David A. Keiter, James C. Beasley, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

ABSTRACT Baiting is a fundamental strategy for the global management of wild pigs (Sus scrofa); however, little information exists on how anthropogenic bait affects wild pig movements on a landscape. We investigated factors that are important in determining the spatial area of attraction for wild pigs to bait (‘area of influence’ of a bait site) using data from Global Positioning System (GPS) collars and locations of bait sites. We monitored movements of wild pigs in 2 distinct study areas in the United States from February to September 2016 and used locational data using GPS collars to analyze the influence of …

A Rapid Population Assessment Method For Wild Pigs Using Baited Cameras At 3 Study Site, Peter E. Schlichting, James C. Beasley, Raoul K. Boughton, Amy J. Davis, Kim M. Pepin, Michael P. Glow, Ryan S. Miller, Kurt C. Vercautern, Jesse S. Lewis

United States Department of Agriculture Wildlife Services: Staff Publications

Reliable and efficient population estimates are a critical need for effective management of invasive wild pigs (Sus scrofa). We evaluated the use of 10‐day camera grids for rapid population assessment (RPA) of wild pigs at 3 study sites that varied in vegetation communities and wild pig densities. Study areas included Buck Island Ranch, Florida; Tejon Ranch, California; and the Savannah River Site, South Carolina, USA, during 2016–2018. Rapid population assessments grids were composed of baited camera traps spaced approximately 500 or 750 m apart. Two RPA grids were deployed per study site and each grid was deployed twice (4–6 months …

Relationships Between Survival And Habitat Suitability Of Semi- Aquatic Mammals, Isidro Barela, Leslie M. Burger, Jimmy Taylor, Kristine O. Evans, Ryo Ogawa, Lance Mcclintic, Guiming Wang

United States Department of Agriculture Wildlife Services: Staff Publications

Spatial distribution and habitat selection are integral to the study of animal ecology. Habitat selection may optimize the fitness of individuals. Hutchinsonian niche theory posits the fundamental niche of species would support the persistence or growth of populations. Although niche-based species distribution models (SDMs) and habitat suitability models (HSMs) such as maximum entropy (Maxent) have demonstrated fair to excellent predictive power, few studies have linked the prediction of HSMs to demographic rates. We aimed to test the prediction of Hutchinsonian niche theory that habitat suitability (i.e., likelihood of occurrence) would be positively related to survival of American beaver (Castor canadensis), …

Effects Of Inactivated Mycobacterium Bovis Vaccination On Molokai-Origin Wild Pigs Experimentally Infected With Virulent M. Bovis, Pauline Nol, Morgan Wehte, Richard A. Bowen, Suelee Robbe-Austerman, Tyler Thacker, Kristina Lantz, Jack Rhyan, Laurie A. Baeten, Ramón A. Juste, Iker A. Sevilla, Christian Gortazar, Joaquín Vicente

United States Department of Agriculture Wildlife Services: Staff Publications

The wild pig population on Molokai, Hawaii, USA is a possible reservoir for bovine tuberculosis, caused by Mycobacterium bovis, and has been implicated in decades past as the source of disease for the island’s domestic cattle. Heat-inactivated vaccines have been effective for reducing disease prevalence in wild boar in Spain and could prove useful for managing M. bovis in Molokai wild pigs. We designed an experiment to test this vaccine in wild pigs of Molokai genetics. Fifteen 3–4-month-old pigs were orally administered 10⁶–10⁷ colony forming units (cfu) of heat-inactivated M. bovis (Vaccinates; n = 8; 0.2 …

Economic Estimates Of Invasive Wild Pig Damage To Crops In 12 Us States, Sophie Mckee, Aaron Anderson, Keith Carlisle, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

We report the results of a survey on invasive wild pig (Sus scrofa L.) damage and control in 12 US states (Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, and Texas). The crops chosen for this study represent the “second-tier” in terms of economic importance after the six crops that were the subject of Anderson et al. (2016). The survey was distributed by the USDA National Agricultural Statistical Service (NASS) in the summer of 2019 to a sample of producers in each of the states (except California) of the following six crops: hay, pecans (Carya …

Rabies Management Implications Based On Raccoon Population Density Indexes, Dennis Slate, Brandi D. Saidy, Ashlee Simmons, Kathleen M. Nelson, Amy Davis, Timothy P. Algeo, Stacey A. Elmore, Richard B. Chipman

United States Department of Agriculture Wildlife Services: Staff Publications

An estimate or index of target species density is important in determining oral rabies vaccination (ORV) bait densities to control and eliminate specific rabies variants. From 1997–2011, we indexed raccoon (Procyon lotor) densities 253 times based on cumulative captures on 163 sites from Maine to Alabama, USA, near ORV zones created to prevent raccoon rabies from spreading to new areas. We conducted indexing under a common cage trapping protocol near the time of annual ORV to aid in bait density decisions. Unique raccoons (n = 8,415) accounted for 68.0% of captures (n = 12,367). We recaptured raccoons 2,669 times. We …

Individual And Population Fitness Consequences Associated With Large Carnivore Use Of Residential Development, Heather Johnson, David L. Lewis, Stewart W. Breck

United States Department of Agriculture Wildlife Services: Staff Publications

Large carnivores are negotiating increasingly developed landscapes, but little is known about how such behavioral plasticity influences their demographic rates and population trends. Some investigators have suggested that the ability of carnivores to behaviorally adapt to human development will enable their persistence, and yet, others have suggested that such landscapes are likely to serve as population sinks or ecological traps. To understand how plasticity in black bear (Ursus americanus) use of residential development influences their population dynamics, we conducted a 6-yr study near Durango, Colorado, USA. Using space-use data on individual bears, we examined the influence of use of residential …

Migratory Flyways May Affect Population Structure In Double‐Crested Cormorants, Steven J.A. Kimble, Brian S. Dorr, Katie C. Hanson-Dorr, Olin E. Rhodes Jr., Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Double‐crested cormorants (Phalacrocorax auritus) recovered from a demographic bottleneck so well that they are now considered a nuisance species at breeding and wintering grounds across the United States and Canada. Management of this species could be improved by refining genetic population boundaries and assigning individuals to their natal population. Further, recent radio‐telemetry data suggest the existence of Interior and Atlantic migratory flyways, which could reduce gene flow and result in substantial genetic isolation. In this study, we used 1,784 individuals collected across the eastern United States, a large panel of microsatellite markers developed for this species, and individuals banded as …

Effects Of Deepwater Horizon Oil On Feather Structure And Thermoregulation In Gulls: Does Rehabilitation Work?, Katherine Horak, Nicole L. Barrett, Jeremy W. Ellis, Emma M. Campbell, Nicholas G. Dannemiller, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Impacts of large-scale oil spills on avian species are far-reaching.While media attention often focuses on lethal impacts, sub-lethal effects and the impacts of rehabilitation receive less attention. The objective of our study was to characterize effects of moderate external oiling and subsequent rehabilitation on feather structure and thermoregulation in gulls. We captured 30 wild ring-billed gulls (Larus delawarensis) and randomly assigned each individual to an experimental group: 1) controls, 2) rehabilitated birds (externally oiled, rehabilitated by washing), or 3) oiled birds (externally oiled, not rehabilitated). We externally oiled birds with weathered MC252 Deepwater Horizon oil (water for controls) …

Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baiting is a fundamental method for delivering toxicants to pest species. Planning baiting strategies is challenging because bait-consumption rates depend on dynamic processes including space use and demographics of the target species. To determine cost-effective strategies for optimizing baiting, we developed a spatially explicit model of population dynamics using field-based measures of wild-pig (Sus scrofa) space use, bait consumption, and mortality probabilities. The most cost-effective baiting strategy depended strongly on the population reduction objective and initial density. A wide range of baiting strategies were cost-effective when the objective was 80% population reduction. In contrast, only a narrow range of …

Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive rats are known to threaten natural resources and human health and safety. Island-wide rat eradication attempts have been increasing in number and scale during the past several decades, as has the frequency of eradication success. The most common method to remove all rats from an island is to broadcast anticoagulant rodenticide bait into every rat’s home range on the island. Broadcast of toxicants can put humans and other nontarget species in marine and terrestrial environments at risk of exposure. The persistence of anticoagulant residues is somewhat unknown, particularly in marine environments. Three years after ~ 18,000 kg of 25 …

Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight

United States Department of Agriculture Wildlife Services: Staff Publications

1. Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE.
2. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient for …

Genetic And Evolutionary Considerations Of The Chronic Wasting Disease – Human Species Barrier, Robert M. Zink

School of Natural Resources: Faculty Publications

Transmissible spongiform encephalopathies can jump species barriers. In relatively few cases is the possible route of transmission thought to be known, mostly involving humans, cattle and sheep. It is thought that sheep might be the cause of Bovine Spongiform Encephalopathy (BSE) and Chronic Wasting Disease (CWD) in cervids, and that humans might have gotten prion disease (e.g., vCJD) from eating meat from BSE+ cows. A looming societal question is whether humans will acquire a prion disease from ingesting prions from CWD+ deer. On an evolutionary tree of the PRNP gene in mammals, deer, sheep and cow are relatively closely related, …

China's Lack Of Animal Welfare Legislation Increases The Risk Of Further Pandemics, Amanda Whitfort

Animal Sentience

Legislation enforcing positive animal welfare standards provides an important buffer against the spread of disease when other safeguards to promote animal health have failed. The continuing absence of animal welfare legislation in China increases the risk of future pandemics, like COVID-19, and puts animal health, and consequently public health in danger.

New Approach To Health And The Environment To Avoid Future Pandemics, Serge Morand

Animal Sentience

This commentary expands Wiebers & Feigin’s target article by pinpointing how declining wildlife, expanding livestock and globalisation contribute to the increase in epidemics of zoonotic diseases, the COVID-19 crisis and future health crises. Epidemics and the emergence of zoonoses are manifestations of dysfunctional links with animals, both wild and domestic, requiring a new approach to health and the environment.

Evaluation Of Rhodococcus Equi Susceptibility To Silver Nanoparticle Antimicrobials, Elizabeth Boudaher

Theses and Dissertations--Veterinary Science

Rhodococcus equi is a significant cause of pneumonia in foals and immunocompromised humans. Antimicrobial resistance among R. equi isolates has developed as a consequence of inappropriate stewardship and bacterial evolution, leading to an increased rate of treatment failures that typically result in foal fatality. In the current study, we evaluated the efficacy of antimicrobial silver nanoparticle (AgNP) complexes in controlling R. equi growth. Previous studies characterizing AgNP-induced antibacterial effects in other Gram-positive pathogens led us to hypothesize that silver nanoparticle antimicrobials impact R. equi viability and intracellular replication. We therefore investigated the effect of silver nanoparticle complexes on R. equi …

Host-Parasite Interaction In Horses: Mucosal Responses To Naturally Acquired Cyathostomin Infections And Anthelmintic Treatment, Ashley Elaine Steuer

Theses and Dissertations--Veterinary Science

Cyathostomins are ubiquitous parasites in equids. In rare cases, cyathostomins lead to a generalized typhlocolitis and death. In healthy horses, local reactions are noted to the mucosal larvae; however, the mechanisms and importance of these reactions have not been elucidated. It has been hypothesized that anthelmintics can alter these reactions. Currently, three drug classes are approved for use in horses against cyathostomins; while all products target the adults, only two products are labeled as larvicidal. Adulticidal therapy is implicated in triggering the typhlocolitis, however, current evidence is contradictory. There is also conjecture that the larvicidal drugs can increase the risk …

Multi-Isotopic (Δ2h, Δ13c, Δ15n) Tracing Of Molt Origin For European Starlings Associated With U.S. Dairies And Feedlots, Scott Werner, J. W. Fischer, Keith A. Hobson

United States Department of Agriculture Wildlife Services: Staff Publications

Introduced bird species can become invasive in agroecosystems and their management is inhibited if their origin and movements are not well understood. Stable isotope measurements of feathers can be used to infer molt origins and interstate movements in North America. We analyzed stable-hydrogen (δ²H), carbon (δ¹³C) and nitrogen (δ ¹⁵N) isotope ratios in feathers to better understand the molt origin of European starlings (Sturnus vulgaris) collected at dairies and feedlots throughout the United States. Primary feathers were used from 596 adult and 90 juvenile starlings collected during winter at dairies …

Tissue Tropisms Of Avian Influenza A Viruses Affect Their Spillovers From Wild Birds To Pigs, Xiaojian Zhang, Fred L. Cunningham, Lei Li, Katie Hanson-Dorr, Liyuan Liu, Kaitlyn Waters, Minhui Guan, Alicia K. Olivier, Brandon S. Schmit, Jacqueline M. Nolting, Andrew S. Bowman, Mia Kim Torchetti, Thomas J. Deliberto, Xiu-Feng Wan

United States Department of Agriculture Wildlife Services: Staff Publications

Wild aquatic birds maintain a large, genetically diverse pool of influenza A viruses (IAVs), which can be transmitted to lower mammals and, ultimately, humans. Through phenotypic analyses of viral replication efficiency, only a small set of avian IAVs were found to replicate well in epithelial cells of the swine upper respiratory tract, and these viruses were shown to infect and cause virus shedding in pigs. Such a phenotypic trait of the viral replication efficiency appears to emerge randomly and is distributed among IAVs across multiple avian species and geographic and temporal orders. It is not determined by receptor binding preference …