ANSC 100

no

Pathogen associated molecular patterns

antibodies in colostrum or given infejtion may be highly effective but dont persist more than a few weeks or months

• recognition and elimination of foreign proteins (antigens) without damaging normal cells and tissues
• Failures result in:
• -tolerance (failure to fight infection) foreign substance was able to invade
• -autoimmune disease (body mounts a reaction against own cells)
• -allergic reaction (exaggertated reaction to non-pathogens), have issues recognising threats and react against non threatening things

• Stress- (can be stimulated by drugs ie cortisol injection = "pharmacologicaly stressed it")
• Body Condition (too skinny or fat)
• Parasitism- gives poor body condition
• Nutrition- cant mount good immune response if doesnt have proper nutrition, or if cow gave birth if not good nutrition she cant give good immuniity to calf through milk

• Copper
• Selenium
• Zinc
• Manganese

• A healthy animal
• effective vaccine given properly

• decreased disease resistance
• if sick then they are slower to recover or they may relapse more
• poorer response to vaccination
• (certain minerals are necessary to produce proper antibodies- give through feed and salt blocks)

weaning, shipping, mixing, diet, weather

• vaccination: the process of giving an injection for the prevention or treatment of infectious diseases
• immunizations: to make the animals immune to something
• difference? vaccination does not guarantee immunity

Looking at different animals its hard to tell which are in health and which have disease because they all develop different immunity

• 1. incubating siease at the time of vaccination (already sick)
• 2. Something happened to the vaccine to make it ineffective
• (ie vaccine not kept in fridge)
• 3. physiologic status of the vaccinated animal may make it less responsive or unresponsive to the vaccine
• 4. The host may be exposed to an overwhelming amount of the infectious agent (too much infection)

• antigenic components (modified or partial form of virus)
• homologous antigens (antigen reacting with the antibody it induced)
• heterologous antigens (antigens that look the same) an antigen that reacts with an antibody that is not the one that induced its formation.
• cross protection (protection of a closely related strain)
• adjuvents- a substance that enhances the body's immune response to an antigen

• environmental/ storage stess
• improper injection equipment
• sterilization practices (ie disinfect but dont rinse out)
• mixing products in syringes (may be incompatible)
• route of injection
• aseptic technique
• *Animals have different responses to vaccines

• 75-80% of the herd must be vaccinated or everyone is at risk
• if not then even those that are vaccinated need a high dose to fight of infection

• Maternal blockade
• immune suppression
• concurrent diseases
• drugs ie corticosteroids
• nutritional status
• age
• hormones
• incubation of disease
• STRESS

• disease that is caused by a living agent (bacteria, viruses, protozoa, fungi)
• although an infectious disease may or may not be contagious- most are transmissinle (ie tetanus, bladder infection)
• time consuming: 5 yrs and therefore expensive to keep animal, and welfare issue

denotes the disturbances caused by entrance growth and activity of the disease causing agent in the body

• vaccine research is complicated
• because the best way to prove it works is to isolate the animals and then expose them to see if they get it

• physical encounter between the host and microorganism
• microorganism colonization of host surface (such as internal gut lining, or external skin)
• microorganisms enter, invade, and spread
• outcome: infection vs the hosts defense

• presence of a pathogenic organism
• the intervening agents (vector or fomite ie towel or boots)
• a portal of entry into the susceptible animal

bacteria, viruses, protozoa, fungi, multicellular parasites

no most are harmless, some are opportunists, while others are quite beneficial or necessary to health maintenance

• -inanimate vectors or fomites: feed & water, transport vehicles, bedding, stalls, troughs, needles and syringes
• -animate vectors: arthropods -flies lice and ticks, mammals- rodents, wild animals, other farm animals, humans

• routes or pathways into the body depends on the enfectious agent and the vector involved
• the most common portals of entry into the body include: into cuts, punctures or abrasions of the skin; through mucus lining, GIT, uro-genital trace

• an animal (host) will inevitably be exposed to pathogenic organisms (agent)
• an animal capable of warding off a particular pathogen are considered "resistant"
• animals in good health normally have primary and secondary defenses that maintain their disease resistance

• collection of statistical tools used to explain the associations of exposures to health outcome
• discover and establish causal (correlation does not mean causation) relationships

Host, agent, environment

• Dose
• pathogenicity
• immune status

Dose: number of bacteria (or virus particles) that challenge the animal

Pathogenicity: organisms's ability to reach the animal, invade and infect, and multiply enough to cause disease (differences in the strains ability to invade)

• invasiveness: the organism's ability to spread from the initial invasion site or to gain entry to the circulatory system
• production of harmful substances: pathogencity of an organism is often due to toxins or enzymes it produces that interfer with the function or metabolism of the animal

immune status: the animals ability to fight off the disease organism (includes primary and secondary defenses)