Disease Flashcards
Disease
An interruption, cessation, or disorder of body functions, systems, or organs
Etiology
The cause or set of causes of a disease or condition
Why is Etiology important?
Animal welfare
Diseases cost the animal agriculture industry
Germ Theory
Disease is caused by microorganisms
Koch’s Postulates
Robert Koch
1. Organism in diseased animal/tissue
2. Culture and grow organism
3. Infect healthy animal -> They need to get sick
4. Re-isolate
Non-infectious Etiologies
Caused by non-living agents
Ex: Nutritional imbalances, Metabolic disorders, Trauma
Poisons/Toxins
Bacterial toxins
Metallic/Chemical toxins -> Ethylene Glycol (Antifreeze)
Phytotoxins
Zootoxins -> Venom
Mycotoxins
Infectious Etiologies
Bacteria
Viruses
Mycoplasma
Protozoa
Fungi
Multicellular Parasites
Characteristics of Bacteria
Prokaryotic -> No nucleus
Can multiply and grow outside animal cells
Forms spores to resist destruction
Contagious -> Less than viruses
Multiple shapes
What are the shapes of bacteria?
Cocci -> Spherical
Bacilli -> Rods
Spiral
Mycoplasma
Classified as bacteria with no cell wall
Moderately contagious
Requires special media and stains
Viruses
Smallest group of pathogenic organisms
Causes illness by destroying cells in the body, transforming them into tumor cells or causing a latent infection
Can only multiply in living cells
Often very contagious
Vulnerable to destruction outside the body
What makes up a virus?
Nucleic acid
Protein coat
Protozoa
Single-celled usually microscopic
Ex: Coccidia, Giardia, Cryptosporidium
Fungi
Eukaryotic
Rigid cell wall, lack chlorophyll
Warm/Damp conditions
Dimorphic -> yeast and mold
Reproduce with spores
