Exam 1 Flashcards
Define Disease
a pathological condition of the body that presents a group of symptoms peculiar to it and which sets the condition apart as an abnormal entity differing from other normal or pathological body states
Define Pathology
study of the nature and cause of disease which involves changes in structure and function
Define Pathologic
Diseased
Define Pathogenesis
origination and development of disease
Define Etiology
the study of the causes of disease
Etiologic (agent)
pertaining to the cause of disease
Epidemiology
science concerned with defining and explaining the interrelationships of factors that determine disease frequency and distribution (population medicine)
Koch’s law
criterion used in proving an organism is the cause of a disease or lesion
Immunology
study of immune function
Immunity
body’s defense against disease
Pathogen
a microorganism or substance capable of causing disease
Parasite
an organism that lives within, upon, or at the expense of another organism, known as the host, without contributing to the survival of the host
Saprophyte
living or growing in decaying or dead matter
Commensal
one of two organisms which live in an intimate, non-parasitic relationship; symbiosis
Zoonosis
a disease that is communicable between humans and animals under natural conditions
Infectious diseases
diseases can be spread from one animal to another or acquired from the environment and involve a pathogenic agent
Non-infectious diseases
diseases are caused by a variety of mechanisms, but do not involve a pathogenic agent
What are 5 infectious agents
•Parasites Protozoa •Bacteria Fungi •Viruses
What are 4 Non-infectious Disease
- Metabolic disturbances
- Nutritional imbalances
- Hormonal disturbances
- Inherited disorders
How does geography and weather affect the occurrence and incidence of disease
Geographical- soil conditions, wet/dry; can dictate occurrence of certain diseases.
Deficient soils can result in deficient forages
Weather- frost on plants can lead to higher occurrence of bloat
What are 4 modes of Transmission of Infectious Agents
- Sexual contact
- Excretions: Urine/feces
- Secretions: vaginal, rectal, lacrimal, nasal, mammary, salivary
- Parasites: Internal/External
Describe how vectors are involved in disease transmission. List 2 common vectors in disease transmission
vectors are animals/insects that carry a disease and transmit it to animals usually through biting.
Ex: bats, ticks, mosquito
List 3 ways infectious agents can be transmitted from a sick animal to a healthy animal
Horizontal
vertical
formites
What is the difference between vertical and horizontal disease. Give and example each
Vertical- passed from parent to offspring ex: in-utero
Horizontal- passed from animal to animal ex: direct contact, nose-nose
Prevalence
proportion of animals with the condition of interest at a given point in time
Incidence
proportion of animals that develop the condition of interest during a defined time period. Number of new cases occurring in a given time period.
Attack rate
proportion of a defined population developing the condition during an outbreak
Bacteriostat
inhibits or retards bacterial growth
Bacteriocide
kills bacteria
Disinfectant
germicidal chemical that destroys microorganisms and the potential infectivity of a material
Antiseptic
mild disinfect used on living tissue
Sanitizer
disinfectant of low toxicity used to reduce microbial contamination of food handling equipment
Sterilize
destroy all microorganisms; physical disinfection
Discuss the “external defenses”, of the skin and GI tract in preventing disease
Urinary tract- flushing
Skin- 1st barrier prevents bacteria or viruses from entering the body
Innate Immunity
- Non-specific, most primitive
- Phagocytosis, consisting of the phagocytic cells of the reticuloendothelial system (Macrophages); Neutrophils, Eosinophils, and Basophils
- Does not alter with repeated exposure
Adaptive Immunity
Specific, more sophisticated
- Includes Lymphocytes, their progeny and their extracellular products
- Improves with each successive exposure to the same pathogen (“Memory”)
List 3 soluble mediator of immunity
antibody
cytokines
complement proteins
Antigen
Any molecule that is recognized by the adaptive immune elements
Antibody
produced in response to an antigen to counteract
List 3 major events of inflammation ? What is “diapedesis”
-Increased blood supply of infected region
-increased capillary permeability permitting larger than normal molecules to breach vessel wall
-leukocytes migrate out of venules into surrounding tissue
Diapedesis: swelling of both feet
Antitoxins
Passive immunization, Immediately protective horse or sheep derived serum Ab, e.g. C. perfringens CD, tetanus;
Toxoid
Inactiviated bacterial toxin, e.g. Clostridium tetani
List 2 properties of modified live virus (MLV) vaccine
less boosters
better/quicker protections
Give 2 examples of why a vaccine might fail to provide protective immunity
denatured vaccine
the animal is already infected with the pathogen
Why do some vaccines require a booster
killed vaccines don’t have as strong of immunity so after some time a booster is needed because it wears off
What is the difference between killed and MLV
MLV: Can induce disease (reversion to virulence), Depressed T-cell function in pregnant animals
Killed: Does not cause disease, Safe in pregnant animals
Passive vs. Adaptive Immunity
Passive: Results from the transfer of Antibodies from one individual to another
Pros: Immediate protection against cell-free infections and toxins
Cons: Short-lived, Expensive
Adaptive: Killed, attenuated, live, modified live vaccines are all capable of conferring active immunity
List 4 important considerations before vaccinating an animal
Pregnancy status
quality of product
colostal interference
state and federal regulations
List 3 reasons why administering a vaccine to an animal may fail to produce a protective immune response in that animal
administering it with the wrong method (SM, IM)
administering in the wrong location on the body
administering the correct amount
Identify: IM, SQ, PO, IN
IM: intramuscular, given under the muscle
SQ: subcutaneous, given under the skin
PO: by mouth, given orally
IN: intranasal, given through the nose
List the four routes of access pathogens can enter the body and cause disease in an animal
urogenital
oral
nasal
eyes
Incubation Period
time between the time length of the agent into the body and when the symptoms show signs
Besides proper nutrition, list 2 other predisposing causes of animal diseases
Age
Stress
List 3 ways pathogens can enter the body of our livestock animals and cause disease
contact- skin
in utero
airborne- respiratory
