Review/Oorsig Volume 22, Issue 02 | Page 30

Oorsig / Review

The 4 Approaches to Disease Prevention

Dr Danie Odendaal – Veterinarian Network
1 .
Increase general resistance ,
2 .
Increase specific resistance ,
3 .
Decrease exposure , and
4 .
Prevent exposure .
As discussed previously , the development process of every disease is different and therefore the prevention or management of every disease also needs a different approach to prevent or interrupt the process .
Basically , 4 approaches are used in the prevention of specific diseases . These approaches can be used as a single approach but in most cases a combination of two or more approaches is used to reduce the risk of disease .
These approaches will now be discussed in the context of disease resistance on a herd health basis .
General Disease Resistance
Within a dairy cattle population , there will be different levels of resistance to a specific disease between animals , even if the animals have not been exposed to the disease before .
If the level of resistance is depicted in a graph it normally forms a “ Bell curve ” - 1 . A few animals have no or little resistance
( left hand side of the curve ). 2 . Most of the animals have an average level of resistance ( middle part of the graph ). 3 . A few animals have very good resistance
( right hand side of the curve ).
In the middle of this graph is a line that depicts the cut-off point which is the minimum resistance needed to prevent the animal from becoming sick .
Cut off point
Susceptible animals
Resistant animals
Low High
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