Nonsteroidal anti-inflammatory drug therapy for neonatal calf diarrhea complex: Effects on calf performance

Todd, C. G.; Millman, S. T.; McKnight, D. R.; Duffield, T. F.; Leslie, K. E.

Sick animals often become anorectic, have an increased threshold for thirst, and have reduced motivation to seek out food and water resources. Hart (1988) examined the biological basis of sickness behavior and argued that anorexia and adipsia are part of a highly evolved strategy to combat infection. Briefly, in response to peripheral infection, mononuclear phagocytic cells secrete proinflammatory cytokines (IL-1β, IL-6, and tumor necrosis factor-α), which carry signals to the central nervous system (CNS) to induce the sickness response (Dantzer, 2001) . In modern livestock production systems, subtle changes in appetite and thirst are often used as behavioral cues to help identify sick animals and opportunities for intervention (Sowell et al., 1999; Thomson and White, 2006; Huzzey et al., 2007; Weary et al., 2009) . However, when sick animals routinely receive supportive care and veterinary treatment, the effects of sickness behavior responses, such as anorexia and adipsia, on convalescence needs to be taken into consideration (Millman, 2007) .