Animal Sanitation Lecture 1-2

Diseases correctly defined as

not at ease, any abnormal condition affecting the body of an organism.

Animal ill health is synonymous with

disease, both describe a structural defect or functional impairment.

Influence of animal death includes

plagues, starvation, sometimes died from same disease that killed their animals

In the plague what was their means of escaping the disease?

migrating to new land but the disease traveled with them within their animals

5 discernible stages in history

primitive ignorance and superstition, accumulation of experience in managing disease, development of verifiable knowledge of the causes of disease, discovery of sulfonamides, penicillin and other antibiotics, and current emphasis directed toward preventative rather than curative measurese

Ancient people believed disease was caused by

demons

In the 1400s

scientist began to suspect that diseases were caused by germs

What was the early name for germs?

living seeds of disease

the cause for infectious diseases has only been known for

100 years

bacteria and other microorganisms were first viewed with a microscope in

1600 but “germ theory wasn’t proved until late 1800s

Germ Theory of Disease

some diseases are caused by microorganisms that are too small to see, invade host, and their growth and reproduction within hosts causes disease

Who proved the germ theory?

robert Koch, Louis Pasteur, Delafond

Robert Koch

father of microbiology and he established criteria proving bacterium caused disease.

Koch’s Postulates

isolate the suspect bacterium in pure culture from diseased animal

expose a healthy animal to bacterium

reisolate the bacterium from the newly infected animal

What did each specific scientist do?

Delafond found blood of sheep that had anthrax, Koch showed animal injected with anthrax got it, Pasteur developed a vaccine to protect animals from anthrax

Disease that aren’t detected til terminal stages have manifested signs called

symptoms

Symptoms

Denotes the disturbance resulting from the entrance growth and activity of disease-causing organisms in or on the animal’s body

Disturbances manifested by these signs

abnormal body temperature, inflammation, depression, anorexia, ab normal breathing, diarrhea, abortion

disease is classified in two major categories

non-infectious and infectious

Non-infectious

caused by nonliving agents and not capable of spreading from one animal to another by direct and indirect contact

Example of a non-infectious disease

nutritional deficiencies, metabolic disorders, trauma, toxic materials, congenital defects

What is a nutritional imbalance and how is it caused?

It is a lack of vitamins, minerals, fats, and amino acids in the animal ration. It can be caused bt inadequate quantity of feed or too much feed and a lack of water.

What can a lack of water lead to?

dehydration which then leads to respiratory and digestive problems

What is a metabolic disorder?

Physiological inability of an animal to make proper use of nutrients. the nutrients can be adequately supplied in the ration but animal cannot properly utilize them

Example of Metabolic Diseases

milk fever (hypocalcemia), grass tetany (hypomagnesia), ketosis

Ketosis

pregnancy disease of ewes which is associated with hypoglycemia

What is trauma?

wounds, damage to body tissues or their function, cuts, tears, burns, bruises, abrasions, sprains, excessive pressure, electrical shock

Toxic Materials

common causes of non-infectious disease in livestock and usually classified on the basis of type of material or organism that caused the poison

Bacterial toxins

poisonous substance produced by bacteria that affect animal health and classified according to how the toxin is released from the bacterial cell

Metallic and Chemical Poisons

Lead, arsenic, fluorine, copper, and salt

Phytotoxins

poisonous substance produced by plants

Example of Phytotoxins

cockle-burs, loco-weeds, sundangrass, Johnson grass, nightshades, oleanders, castor-beans, and ferns

Zootoxins

toxic substances that are produced by certain snakes, spiders, and bees

Mycotoxins

toxin producing fungi or molds

Examples of Mycotoxins

peanuts, brazil nuts, corn, and most other cereal grains

Some non-infectious diseases are

congenital defects, abnormalities before or at birth, misplaced limbs, and white heifer disease

white heifer disease

causes reproductive issues sterility

Infectious disease are caused

by an infectious agent

Infectious agents are

bacteria, viruses, protozoa, or fungi

Infection

colonization of a host organisms by a foreign species and seeks to use the host’s resources to multiply

Infectious diseases are

communicable (from one animal to another), can or can’t be contagious, easily transmitted by contact, and non-contagious infectious disease

What are microbes

bacteria, viruses, prions

What makes up most of our oxygen?

photosynthetic bacteria which fixes carbon into a usable form

Resistant Animals

animals that are capable of warding off specific pathogens

Resistence depends on

physical condition of the animal and ability of animal to fight off invading organisms

Susceptibility

A lack of resistance

What are the two types of bodily defenses that keep resistance high in

primary and secondary

external and internal

Primary defenses

Skin and Mucous membranes

Skin

provides protective armors for the delicate and susceptible parts of the animal’s body

Mucous membranes

line the soft tissues of openings to the body

Ingested organisms\*\*

What are the bodily defenses?

Respiratory tract: expels by coughing and passed into digestive tract

Secretions from the tear glands trap and wash out invaders

Organisms in urinary tract get washed out by urine

Secondary Defenses

antibodies and phagocytes

Antibodies

substances produced by an animal in response to the presence of protein-like substances called antigens

Phagocyte

cells that ingest microorganisms or other cells and come in two types

Fixed Phagocytes

Line the blood vessels in the liver, spleen and bone marrow and attacks organisms that pass their way.

Free phagocytes

white blood cells that rush to the site of infection to combat foreign invaders.

What happens to invading organisms once they enter an animal’s body?

can be destroyed by body’s defense mechanism, eliminated from body, may cause disease, grow and multiply in the animal’s body tissues

Chronic Infection

if infection persists and gradually wears down an animal’s resistance

Acute Infection

pathogenicity of invading organisms rapidly over power the animals resistance

Sometimes invading organisms and host

can live without serious harm to one another.

Elimination by host

organisms expelled through secretions of infected animals

Secretions and excretions from infected animals are

common means of spreading diseases of livestock

Destruction with Carcass

invading organisms perish if the host dies and proper disposal of the carcass is vital to prevent spreading of disease

Disposal of carcass

removal incineration or burial (disinfect where carcass was)

If they can be transferred to humans

they are called zoonoses

Portals of entry for microorganisms

cuts, punctures, abrasions of the skin, mucous linings of the respiratory tract, eyes, mouth, navel, gastrointestinal tract, and genitourinary tract

Some microorganisms can only cause disease

if they enter through a specific portal

Vector

transmitting agent or anything that allows transport of a microorganism

Inanimate

contaminated feed, water, troughs, buckets, needles, syringes, fence posts, stalls, bedding, feces, urine, and saliva

Animate (animal vectors)

arthropods, mammals, including humans, flies, ricks, lice, dogs, rats, wild animals, farm animals

Characteristics of Microorganisms that cause disease

pathogens, parasitic and motivated for survival, no evil intent, cause disease simply because they are able to live on or in bodies of animals, saprophytes

Microorganisms that are beneficial

bacterial, yeasts, and molds

extremely importantly to manufactures of cheese, alcohol, butter, solvents for paints and oils, and other products

Bacterial yeasts and mold play a vital role

in maintaining and improving soil fertility by decomposing organic matter and changing nitrogen into available plant usage

Bacteria

single celled microscopic organisms that are spherical and rod-shaped

Bacteria Patterns

streptocci, staphylococci, diplococci, and tetrads

Streptococci

rows of cells in a chain like arrangement

Staphylococci

irregular cluster of cells

Diplococci

pairs of cells

tetrads

four cells arranged as squares

Rod-shaped bacteria

bacillus cylindrical in form, ends may be rounded, flat, or pointed

Spiral shaped

known as spirillium, cork-screw shaped, spirochete, comma shaped

Filament shaped

longed, slender, threadlike

Spores

two types of bacteria are capable of producing spores

Diseases Spores Cause

anthrax, enterotoxaemia, tetanus

Spores are resistant to

heat, dessication, chemical disinfectants

Flagella

helps movement in liquid, delicate, threadlike appendage

What do bacteria require fo rgrowth?

suitable temperature (70-100 F), moisture, darkness, and food nutrients

Fungi

do not contain chlorophyll, cant make own food, depend on plants and animals to live

Fungi includes

molds, yeasts, mildews, and toadstools

beneficial fungi

maintenance of soil fertility and penicillium mold but some are pathogenic

viruses

small microorganisms that cause infectious disease and must have living cells to parasitize

Protozoa

single celled animals that are microscopic in size

ex amoeba

Lost from disease comes from

lowered production, reduced growth rate, sterility, abortion, unnecessary cost of feed additives and medicine, and death

Goal of prevention programs should

avoid spread, reduce stress, increase reproductive performance, and ensure survival of newborn

Practical means of disease control

increase resistance to a certain disease and decrease the disease challenge

keep resistance above disease resistance challenge level

proper and natural acquired resistance, maternal antibody production, parasite control, and nutrition

Stress\*\*

lowers the immune system and causes resistance to decrease

ex: weaning, transportation, overcrowding, parasites, and poor nutrition

The disease challenge can be increased by

sick animals shedding, spreading viruses to nearby animals, environment is conductive to rapid growth and transmission of disease

For a healthy herd

work at increasing resistance, limit stress, and level of disease challenge