Disease is the interaction between three variables:

• Opportunity: The amount of exposure to a pathogen, or disease-causing agent. This can be managed by proper housing, isolation of sick animals within a herd, and herd surveillance. These strategies can help minimize the exposure of your herd.
  
  
• Pathogen Virulence: Every pathogen has a different mode and efficiency of transmission from one animal to another. Identifying specific disease-causing agents can help us most efficiently control the spread of the disease.
  
  
• Immunity: This is an individual or herd's ability to resist disease. Vaccination is the primary method by which we can increase a herd's immunity. Other important factors influencing an animal's or herd's immunity include an adequate plane of nutrition and proper husbandry; i.e., foot and dental care.

Because disease prevention involves the interaction and control of these factors, it is important to custom design a herd health schedule for your individual operation. For example, say Farm A is having an outbreak of calf scours. Upon reviewing the vaccination program, there is room to get more aggressive by increasing the number of vaccinations. However, it is also clear that Farm A has major gaps in farm husbandry--dirty calving pen, unsanitary condition of calf housing. In this case, hyperimmunizing, or increasing vaccination, is not going to have a significant effect on calf health until steps are taken to improve sanitation.

The above scenario applies to all livestock species and highlights the importance of tailoring an all-encompassing herd health program to your individual operation.

Please contact us with questions about this principle or to schedule an appointment to discuss your operation.