Chapter 5 Threats
5.13 Disease and Pathogens
This threat focuses on diseases, viruses, bacteria, prions, and other pathogens that can affect wildlife species. Some topics are wildlife specific, while others may not normally infect wildlife but can be carried over from other vectors. All wildlife species are subject to some type of naturally occurring disease that can cause illness and death to individual animals or in some cases can significantly impact population densities (McLean 2005) . It has been reported that disease resistance depends on the interaction of host, pathogens, and environment (Snieszko 1970) . This subsection provides information about some of the most serious diseases or emerging concerns that can significantly impact wildlife species or create spillover effects to humans. The following information highlights some of the important concerns and identifies resources for additional information. Disease management strategies for wildlife generally fall within three categories: prevention of introduction, control of existing disease, and eradication (Wobeser 2002) . In many cases, the spread of disease among and between species is controlled naturally and there is little risk of extinction when mortality occurs within a population. However, management actions to control the incidence and spread of disease may be warranted when disease impacts are so severe that local populations are at risk of becoming extinct; or when mortality from diseases is so severe that it affects ecological processes and/or exceeds the social capacity for acceptance. Management may also be warranted when genetic flow is disrupted between populations or when there is a risk of spillover to human or domestic animal populations. Wildlife can serve as a reservoir for diseases and pathogens that naturally occur within wildlife populations with little effect on populations, but which have the potential to create spillover effects that affect human health. Examples of diseases that can spillover from wildlife to humans include tickborne diseases (e.g., Lyme disease, Ehrlichiosis , Rocky Mountain Spotted Fever), leprosy, brucellosis, ebola, rabies, and hantaviruses to name a few. Newly introduced diseases can be carried by exotic, nonnative species or captive-raised animals that have been released to the wild. Unnatural high densities facilitated by wildlife feeding and baiting can lead to increased densities of wildlife species and comingling, increasing the prevalence and transmission rates of wildlife disease. When disease in wildlife is associated with human behaviors, steps to educate the public and reduce the incidence of such behaviors should be implemented in an effective way. In some cases, wildlife may develop diseases or conditions they would not normally have but which are the result of human-induced conditions. Examples include the incidence of pancreatic cancer, diabetes, intersex malformations, and tooth decay. Black Bears have been found with tooth decay likely caused by consumption of bait foods containing high concentrations of sugar. Another example is freshwater fish species that exhibit intersex
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2025 NC Wildlife Action Plan
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