Exam 5

Wildlife diseases

  • Disease

    • departure from a state of health

    • alteration in structure/function of organism

Why study disease?

  • Public relations value

    • especially with :

      • zoonoses (zoonotic diseases, can be transmitted to humans)

      • diseases that affect domestic animals (livestock mostly bc economic, but also pets)

  • Role of disease in population ecology

  • Diseases can play a sentinel role in populations

    • may indicate something else or other problems in the environment


Signs vs. Symptoms

  • Signs - things we can see

    • ex - ducks body posture and botulism

  • Symptoms - something the animal senses but we might not see obviously

    • ex - sore throat

    • ex - canada goose - green staining around vent - lead poisoning


How common are wildlife diseases?

  • pretty common, but many not of much significance

  • diseases w mild signs may go unnoticed


CATEGORIES OF DISEASES

  • Infectious

  • Non-infectious


Infectious - transmitted from one biological agent to another (susceptible host or by vector)

  • microparasites, viruses, fungi, pryons - acute disease, kill or affect organism quickly

  • macroparasites - chronic, “less dramatic affects than the micro”

Non-infectious - not caused from biological agents

  • poison, congenital, cancer, trauma, etc


Tasmanian devil tumor disease - infectious


Disease Terminology

  • Morbidity - showing signs of being sick

  • Enzootic - disease of low morbidity (dont have too many in pop sick at one time) (on graph, line just straight across, pretty even)

  • Epizootic - disease of high morbidity (higher morbid rate) (disease not present, then big spike, then gone)

____/\_____

  • epizootiology - study of how, when, and why disease occurs

  • lesion - some physical evidence of a disease (area of abnormal tissue, tumor, wound, abscess, etc)

    • rabbits and their livers

  • pathogenesis - the normal course of the disease from the beginning

    • most diseases follow a particular sequence of events

  • determinant - any factor out in the environment that when altered changes the nature of the disease. frequency or behavior of the disease

  • incubation period (infectious diseases) - time between infection and when you have onset of disease (become sick, departure from health)

  • latent period - time between infection and ability to shed the disease (pass to others)

  • vector - typically some invert transmits disease between and within populations

  • reservoir

    • living and nonliving