A therapeutic strategy for treatment of the bovine respiratory disease complex: The rationale for the combination of a nonsteroidal anti-inflammatory drug with an antibiotic

The bovine respiratory disease complex (BRDC) can be caused by a number of factors involving the animal, its environment, and the presence of infectious agents. The syndrome can be classified into four grades: Grade 1, subclinical disease; Grade 2, compensated clinical disease; Grade 3, noncompensated clinical disease; and Grade 4, irreversible clinical disease, which threatens the animal's survival. The predisposition of cattle, especially beef calves, to respiratory problems is related to their lack of functional pulmonary hardiness. Selection of breeds that demonstrate adequate pulmonary function and sufficient ventilatory reserve may help in the control of BRDC, but this approach is difficult to implement and slow to produce results. Prophylactic measures, including vaccination programmes and modifying management practices to reduce stress, also have a place in prevention of BRDC. A therapeutic strategy to minimise the economic impact of BRDC includes the use of appropriate antibacterial therapy, modulation of the pulmonary inflammatory reaction, and correction of mechanical disorders. Most cattle affected by BRDC are classified as Grade 3. In these cases, irreversible damage to the lung can only be avoided by simultaneous control of bacterial infection and local inflammation. The basic therapeutic strategy described in this article involves the combination of an antibiotic, such as florfenicol, to act against the relevant pathogens and a nonsteroidal anti-inflammatory drug (NSAID), such as flunixin, to act against the deleterious effects of inflammation