lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Veterinary epidemiology
L1: Health & disease
Ch1, Ch6 & Ch27
Health => relative concept with many definitions (ADP, health = ability to adapt)
WHO (World Health Organization): definition health => physical, psychological & social well-
being
Status of animal
o Diseased or healthy
o Is not easy to determine due to relative concept of health
o Even if it is not relative concept: expert can still not indicate status in all cases
- Subclinical disease => cannot be observed with naked eye (symptomless)
Homeostasis (adaptive capacity)=> temporary or permanent anatomical, physiological or behavioral
change of organism to reduce or overcome health-threatening influences
Specific: e.g. high environmental temperature, perspiration 1
Aspecific: stress, non-specific reaction to stimulus (=stressor)
Stress => body’s response to any stimulus
Stress reaction should not always be avoided
- Allows animal to live with suboptimal conditions
Stimulus persists for long time: it can have negative consequences
- Stress control = symptom control
- Better to remove cause (stimulus/stressor)
Stressor => stimulus that induces stress response
General adaption syndrome => activation of
hypothalamic-pituitary-adrenal circuit (endocrinology)
1. Alarm
- 1st slight drop to below normal, then
increase above normal
2. Resistance
- Adaption
3. Exhaustion
- Long term exposure to same stressor ->
death
1
Zweten
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Risk of disease -> higher in highly productive animals
o High production affects adaptive capacity in negative way
Adaptive capacity influenced by:
Internal (animal itself)
- Genetic constitution (environmental needs, adaptive capacity)
- Production stage (age, sex, reproduction stage)
External (environment)
- Abiotic environment = dead environment (nutrition, housing, climate)
- Biotic environment = living (pathogens, non-pathogens, social environment)
Levels of disease
1. Subclinical disease
- Symptomless
2. Clinical disease
- Visible symptoms
From clinical symptoms -> (probability) diagnosis is made
Each symptom not specific to any disease: e.g. fever occurs in several diseases
Sometimes whole set of symptoms more specific -> but in most cases even that is not specific
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Clinical health characteristics & anomalies2 in clinical disease
Body temperature -> normal limits per animal species
- Hyperthermia: fever
- Hypothermia: undercooling
Digestion
- Appetite
- Excretion of manure (diarrhoea, constipation)
- Rumination
Respiration = breathing
- Frequency & type
Behaviour
Gait & posture
- 1 or more legs
Condition
- Result of health
- Production & nutrition
- Fat-meat cover
Skin, hair & feathers
- Colour & shine
- Scabies3 & mould4
Circulation
- Heart rate
- Oedema
Mucous membranes
- Colour & moisture
Production
- Sudden drop
Odour
- Foot rot
- Hypocalcaemia (milk fever)
Who makes (probability) diagnoses?
Animal holder => inspects daily
o Questions or problems: veterinarian called in
o Sometimes: governments has to step in & help prevent/combat disease
- Disease is exceptionally infectious or dangerous
- Disease can cause damage to other farming businesses & economy or pose threat to
public health
o Livestock farmers must:
- Ensure adequate hygiene
- Be alert to symptoms
- Report animal diseases to Netherlands Food & Consumer Product Safety Authority
2
Anomalies = afwijkingen
3
Scabies = schurft
4
Mold = schimmel
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
- Comply with requirements when importing animals from countries outside EU
- Vaccinate animals
Veterinarian => treatment of diseased or infected animals. In case of deviations from normal ->
animals examined by Animal Health Service (AHS)
o Diagnose animal diseases
o Play important role in monitoring & surveillance of public health
- Often 1st to establish outbreak of contagious animal disease -> contribute to control of
epidemics
- Give advice on combatting, preventing & controlling animals diseases to livestock
farmers
Animal health service (AHS) in NL
Also collects signals of new signs of disease in animals
Additional diagnostic tests to confirm probability diagnosis
Blood test
Secreta/excreta (faeces etc)
- Poison, pH, blood in urine
Autopsy (post-mortem examination)
- Evaluation organs
Blood test => serological test
3 types:
1. Pathogen (=antigen)
2. Antibodies
3. Blood composition (e.g. enzymes)
Relatively fast,easy & cheap
False-positive & false-negative results:
- False+ => not infected, but scores positive
vaccination, cross-reaction, infection gone but antibodies still present
- False- => infected, but scores negative
latency time, tolerance
Importance disease (control)
1. Economics
2. Public health (zoonoses)
3. Animal welfare
4. Quality of animal product
Zoonoses => infectious disease transmitted from animals to humans (~60% of human diseases)
Gedownload door Michou Weimar ()
Wondershare
Verwijder Watermerk
PDFelement
Veterinary epidemiology
L1: Health & disease
Ch1, Ch6 & Ch27
Health => relative concept with many definitions (ADP, health = ability to adapt)
WHO (World Health Organization): definition health => physical, psychological & social well-
being
Status of animal
o Diseased or healthy
o Is not easy to determine due to relative concept of health
o Even if it is not relative concept: expert can still not indicate status in all cases
- Subclinical disease => cannot be observed with naked eye (symptomless)
Homeostasis (adaptive capacity)=> temporary or permanent anatomical, physiological or behavioral
change of organism to reduce or overcome health-threatening influences
Specific: e.g. high environmental temperature, perspiration 1
Aspecific: stress, non-specific reaction to stimulus (=stressor)
Stress => body’s response to any stimulus
Stress reaction should not always be avoided
- Allows animal to live with suboptimal conditions
Stimulus persists for long time: it can have negative consequences
- Stress control = symptom control
- Better to remove cause (stimulus/stressor)
Stressor => stimulus that induces stress response
General adaption syndrome => activation of
hypothalamic-pituitary-adrenal circuit (endocrinology)
1. Alarm
- 1st slight drop to below normal, then
increase above normal
2. Resistance
- Adaption
3. Exhaustion
- Long term exposure to same stressor ->
death
1
Zweten
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Risk of disease -> higher in highly productive animals
o High production affects adaptive capacity in negative way
Adaptive capacity influenced by:
Internal (animal itself)
- Genetic constitution (environmental needs, adaptive capacity)
- Production stage (age, sex, reproduction stage)
External (environment)
- Abiotic environment = dead environment (nutrition, housing, climate)
- Biotic environment = living (pathogens, non-pathogens, social environment)
Levels of disease
1. Subclinical disease
- Symptomless
2. Clinical disease
- Visible symptoms
From clinical symptoms -> (probability) diagnosis is made
Each symptom not specific to any disease: e.g. fever occurs in several diseases
Sometimes whole set of symptoms more specific -> but in most cases even that is not specific
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Clinical health characteristics & anomalies2 in clinical disease
Body temperature -> normal limits per animal species
- Hyperthermia: fever
- Hypothermia: undercooling
Digestion
- Appetite
- Excretion of manure (diarrhoea, constipation)
- Rumination
Respiration = breathing
- Frequency & type
Behaviour
Gait & posture
- 1 or more legs
Condition
- Result of health
- Production & nutrition
- Fat-meat cover
Skin, hair & feathers
- Colour & shine
- Scabies3 & mould4
Circulation
- Heart rate
- Oedema
Mucous membranes
- Colour & moisture
Production
- Sudden drop
Odour
- Foot rot
- Hypocalcaemia (milk fever)
Who makes (probability) diagnoses?
Animal holder => inspects daily
o Questions or problems: veterinarian called in
o Sometimes: governments has to step in & help prevent/combat disease
- Disease is exceptionally infectious or dangerous
- Disease can cause damage to other farming businesses & economy or pose threat to
public health
o Livestock farmers must:
- Ensure adequate hygiene
- Be alert to symptoms
- Report animal diseases to Netherlands Food & Consumer Product Safety Authority
2
Anomalies = afwijkingen
3
Scabies = schurft
4
Mold = schimmel
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
- Comply with requirements when importing animals from countries outside EU
- Vaccinate animals
Veterinarian => treatment of diseased or infected animals. In case of deviations from normal ->
animals examined by Animal Health Service (AHS)
o Diagnose animal diseases
o Play important role in monitoring & surveillance of public health
- Often 1st to establish outbreak of contagious animal disease -> contribute to control of
epidemics
- Give advice on combatting, preventing & controlling animals diseases to livestock
farmers
Animal health service (AHS) in NL
Also collects signals of new signs of disease in animals
Additional diagnostic tests to confirm probability diagnosis
Blood test
Secreta/excreta (faeces etc)
- Poison, pH, blood in urine
Autopsy (post-mortem examination)
- Evaluation organs
Blood test => serological test
3 types:
1. Pathogen (=antigen)
2. Antibodies
3. Blood composition (e.g. enzymes)
Relatively fast,easy & cheap
False-positive & false-negative results:
- False+ => not infected, but scores positive
vaccination, cross-reaction, infection gone but antibodies still present
- False- => infected, but scores negative
latency time, tolerance
Importance disease (control)
1. Economics
2. Public health (zoonoses)
3. Animal welfare
4. Quality of animal product
Zoonoses => infectious disease transmitted from animals to humans (~60% of human diseases)
Gedownload door Michou Weimar ()
