ruminant herd health Flashcards
(54 cards)
What is monitoring?
a continuous effort to collect data to detect changes or trends int he occurence in order to inform descisions
What is surveillance?
a special case of monitoring where data is used to assess a a status in response to a pre-define threshold
what are the 8 steps in surveillance?
1) objectives
2) hazard selection
3) case definition, diagnostic methods
4) target pop’n
5) timing, sapling interval
6) data management, analysis
7) methods for data analysis
8) feedback
How is incidence calculated?
incidence (rate) = no of new cases / pop’n at risk x time at risk
how is prevalence calculated?
prevalence (proportion) = no of exsisting cases / pop’n at risk
what is bias?
a systematic error due to the design, implementation or the analysis of the surveillance program
What is a zoonoses?
disease which are naturally transmitted between vertebrate animals and humans
what is a carrier?
pathogens isolated from animal/human without causing clinical signs of diesease in the host ( 1sample)
what is a colonised host?
no clinical signs on the host but implies that microbes are multiplying on the host .. need longitudinal sampling
what is a reservoir?
the spread of an organism within the reservoir host to maintain the pathogen indefinitely
What are our responsibilities to zoonoses?
1) early suspicion and correct diagnosis
2) client communication
3) prevent spread
how in food animals is the risk assessment for zoonoses carried out?
risk assessment = probability of inf ( prevalance of hazard and transmission pathway) + consequence of exposure
What is a hazard?
an agent, substance or action that has the potential to cause an undesired event
What is a risk?
the probability of an undesired event and the consequences of it
What is risk management?
interrupting, preventing or eliminating transmission pathways identified in the assessment
4 mains strategies for risk management
1) risk transfer (insure)
2) risk avoidance (dont perform hazardous activities)
3) risk mitigation / reduction (agree target)
4) risk acceptance ( do nothing if below target)
why do we carry out surveillance?
1) effetiveness of statutory disease control
2) protect public health
3) understand and measure the impact of animal disease on climate change
4) detection of new / re-emerging disease, infection and toxicity
5) providing assurance of freedom from specified disease
6) detection of incursion of an exotic disease
7 steps in a herd / flock investigation
1) define the problem
2) history taking
3) a - environment exam
b - distance flock exam
4) a - individual animal exam (full vs basic - mucus membranes, weight, BCS)
b - post mortem exam
5) further diagnostic test
6) data analysis and decision making
7) reporting back and future monitoring
problem with poor thrift in young animals?
longer to reach slaughter weight so more expensive
target calf / lamb growth rates
calf = 1-3 kg / day lamb = 100-300 g/ day
problem with adults being thin at mating
longer anoestrus
lower conception rates
less ovulation rate (fewer twins)
problem with adults being thin in early pregnancy
less placental development
problem with adults being thin in late pregnancy
increased risk of metabolic disease
problem with adults being thin during lactation
less milk yield
