Effectiveness of tilmicosin phosphate (Pulmotil~R AC) for controlling respiratory disease associated with Mycoplasma hyopneumoniae in swine in the presence of porcine reproductive and respiratory synd

摘要

Swine respiratory disease (SRD) is associated with multiple bacterial and viral respiratory pathogens. Clinical disease is characterized by decreased rate of growth, decreased feed efficiency, anorexia, fever, dyspnea, and mortality. In the field, co-infections of multiple bacteria (e.g., Mycoplasma hyopneumoniae) with or without viral pathogens (e.g., PRRSV) are common and a leading cause of SRD. Experimental models have demonstrated that a single infection with either Mycoplasma hyopneumoniae (M hyo) or a viral pathogen usually results in mild or unapparent and transient disease.1 However, it has also been demonstrated that M hyo infections potentiate the severity and the duration of disease in animals co-infected with porcine reproductive and respiratory syndrome virus (PRRSV) supporting the criticality of controlling M hyo in herds affected with PRRSV.1 Tilmicosin phosphate (Pulmotil~R AC) was approved in the US in Spring 2014 for the control of swine respiratory disease associated with Pasteurella multocida and Haemophilusparasuis in groups of swine in buildings where a respiratory disease outbreak is diagnosed.2 Tilmicosin has also been shown to have antimicrobial effects against M hyo in in vitro settings.3 Therefore, this study evaluated the effectiveness of tilmicosin phosphate administered via the drinking water for controlling respiratory disease associated with M hyo in swine in the presence of PRRSV.