**3. Ruminants health and economics**

Outbreak of any disease adversely affects the livestock production starting a process that progressively leads to low production and little profit. Animal diseases in livestock are mostly multifaceted and affect all the persons involved in food chain starting from livestock owner to the livestock product consumer. These diseases affect the economy through various ways, including decreased production, increase cost of treatment, market disturbances, a ban on the transportation of livestock products, limited tourism, and prevention and control expense [6].

If we take an example of foot and mouth disease (FMD), a disease of low mortality, but the worldwide impact of FMD is massive due to a larger number of animals affected by disease [7]. The losses due to FMD can be subdivided into direct losses because of decreased production and indirect losses due to expenses of FMD control and limited access to markets [8]. It is estimated that outbreaks of FMD in FMD free countries and zones can result in loss of >US\$1.5 billion per year. FMD endemic countries suffer annually between US\$6.5 and 21 billion due to production losses and vaccination [9]. Foot and mouth disease outbreak in the UK in 2001 resulted in the slaughter of 6 million animals [10].

Mastitis is another major problem of dairy animals that negatively affects the production. This directly lessens the net profit due to treatment expenses, reduced milk production, and quality of milk. Indirect impacts of disease include decreased fertility, increased culling rate, and rarely mortality [11]. Globally, published data regarding the economic losses of clinical mastitis depict the loss from €61 to €97 per cow on a farm, depending upon preventive practices. For example, in The Netherlands, economic losses due to clinical and subclinical mastitis varies from €17 to €198 per cow per year [3].

Bovine respiratory disease (BRD) is the most common disease among the feedlot cattle. BRD causes an estimated \$800 million to \$900 million annually in economic losses from death, reduced feed efficiency, and treatment costs [12]. Peste des petits Ruminants virus causes large economic losses each year due to high mortality and morbidity rates in the infected sheep and goats and outbreaks were more severe in goats than sheep. Global estimated impact due to this disease is in between US\$1.4 and 2.1 billion [13].
