Livestock Health

Animal diseases constitute a major constraint to livestock production and the safe utilization of animal products worldwide. For the poor, the impact of livestock disease on lives and livelihoods is particularly severe. Indeed, an outbreak of disease can mean the difference between sufficient food stocks and food insecurity, between having a secure income to the loss of key household assets. The presence of livestock disease also makes it difficult for the poor to participate in local and even the national livestock economy. In this manner, households are further marginalized from securing safe and sustainable livelihoods. Equally importantly, animal health and human health are intricately related. Zoonotic disease can have a major influence on the health and wellbeing of the households involved. Hence, livestock disease has a major influence on poverty outcomes.

Epidemic Disease Endemic and Parasitic Disease Trans-boundary Diseases Zoonoses and Zoonotic Diseases Diseases in Poultry Health and Nutrition Interactions Diseases Related to Production and Management References and Further Reading

Recognizing the effect of specific livestock diseases on the livelihoods of the poor, whilst clearly important, is not enough on its own. To address the impact of livestock disease on the poor, issues relating to the delivery of animal healthcare services must also be dealt with. Furthermore, actions for development take place in a wider policy environment. Hence, policies regarding the livestock health sector in general also need to be considered.

These sections aim to provide information about important endemic, epidemic and zoonotic diseases within a context of the wider issues impacting the control and management of animal health in southern countries. Hence, delivery, public health, awareness, and policy issues, as well as social, cultural and economic issues, must also be seen as being important.

As Figure 1 below illustrates, livestock disease is the result of the complex interaction between the agent, the host and the environment in which it takes place. Indeed, referred to as the Epidemiological Triad, any consideration of animal health must take into account these factors.

For example, the agent factors important to disease transmission include: the virulence and infectivity and the ability of the agent to survive in the environment. Whereas, the host factors key to presence of disease include the immune response, age, sex, lactation and pregnancy status, phenotype etc. Finally, in Southern countries, the husbandry and management environment often have the largest link to animal health. As such, environmental factors include: the stocking density, housing sanitation and ventilation, exposure to other herds or movement between herds, temperature, humidity or heat or snow/rain or the level of nutrition. The figure below illustrates the Epidemiological Triad.

In addiiton, it is very important to understand that the wider context in which animal disease occurs must be acknowledged. Indeed, there has been a resurgence of serious infectious livestock diseases and veterinary public-health problems throughout the world. This trend is likely to continue in the future. There is also the challenge of new diseases and new manifestations of existing diseases, the result of changing epidemiological circumstances and changing livestock husbandry and trading patterns. Whilst this is a major challenge for developed and developing countries alike, developing countries are recognized as being particularly vulnerable. The livelihoods and health of poor livestock farmers and farming communities in such countries are under threat from these disease risks.

Martin, W., Meek, W. and Willeburg, P. (1987). Veterinary Epidemiology: Principles and methods. Iowa State University Press. Ames, Iowa.

Smith, R.D. (1995). Veterinary Clinical Epidemiology: A problem oriented approach. CRC Press, Boca Raton, Florida .