Modern Definition of Health

• the result of interacting biological, social and environmental factors, they work together to promote, maintain and adopt the health of an animal

• you cannot measure wildlife health only by what is absent, it requires a broad understanding of ecosystem/individual and their vulnerabilities and resilience

• NOT a biological state, but instead a human construct that includes:

  • measures and management of hazards

  • determinants of population vulnerabilities

  • resilience in wildlife health programs

  - approach acts proactively to maintain health rather than reactive to disease

Environmental Impacts on Vectors

• life cycles of vectors are strongly influenced by temperature and humidity

  • increased temperatures = increased speed of vector development (aka more vectors)

  • this increases the rate of vector borne disease

Finding Food and Nutrition

• can become difficult due to:

  • pollution increase

  • changes in food sources

  • competition increase

  • energy output increase

  • nutritional requirements increase

• all of the above can be caused by human modifications and land use

Avoiding Predation

• anti-predator responses negatively affect free-living wildlife

  • fecundity

  • early offspring survival

Handling Parasitic Load

• animals differ in the number of parasites they encounter and host

• this can affect animals:

  • immune system

  • physiology

  • behaviour

• trophically transmitted parasites can alter host’s predator avoidance or risk-taking behaviours

ANIMAL DISEASE SPECTRUM

• all can be found within a population at the same time

  • Death

  • Severe Clinical

  • Mild Clinical

  • Asymptomatic

Affects on Disease have on Animals

• reducing growth

• reducing reproductive rates

• increasing metabolic needs

• changing behaviour

• causing death

Increase in Wildlife Disease

• cases/events are increasing

• there is an expanding interface between humans and animals

• both these are likely due to:

  • habitat loss

  • climate change

  • global movement of people and vectors

  • improved diagnostics

WHY Study Wildlife Disease

• understand impacts on wildlife and to aid management

  • to determine significance of disease, identify method to reduce it or its impacts

• human or agricultural importance

  • contribute to huge agricultural loss due to wild strains of disease

• relates to environmental health and habitat loss

  • indicate environmental contamination can cause habitat loss and increase disease transmission

• high visibility or public concern

  • its icky to look at and freaks out the public which requires communication

HOW We Study Wildlife Disease?

• diagnostic investigations

• surveillance for pathogens or disease

  • passive or active surveillance

Challenges to Studying Wildlife Disease

• funding

• detecting sick and dead animals

• obtaining samples

• quality of samples

• quantifying disease

• lack of knowledge

• lack of validated diagnostics

Management of Wildlife Disease?

• prevention

• control

• eradication

DISTRIBUTION

• who: (demographic)

  • species, taxonomic group

  • age

  • sex

  • behaviour

  • nutrition

  • con-infection

• what:

  • the causes of disease

    • characterize clinical and pathologic features of disease identify if its non-infectious or infectious

      • multifactorial remember

• when:

  • the temporal disease patterns

  • very important to define

    • clustering of cases

    • seasonality

    • associations with other events/biology

    • change over time

      • two temporal patterns

        • enzootic

        • epizootic

• where:

  • location of environment

  • various levels:

    • entire spatial area ~ country

    • distribution within area ~ province

    • environment ~ habitat

    • smaller (pathogenic agent) ~ locale or animal

• why:

  • why and how is occurs

  • pathogenesis of the disease allows us to determine underlying and predisposing factors