Efficacy of intramuscular tylosin for the treatment and control of porcine proliferative enteropathy caused by Lawsonia intracellularis.

This double-blind study investigated the efficacy of injectable tylosin (Tylan 200 injection, Elanco Animal Health, Indianapolis, IN) for the treatment and control of porcine proliferative enteropathy caused by Lawsonia intracellularis using a mucosal challenge model. Intramuscular (IM) tylosin was compared with sterile tylosin injection carrier (negative control). IM treatments (1 mL/22.5 kg [50 lb body weight; 4 mg/lb body weight]) were administered to two groups of pigs twice daily for 3 consecutive days, commencing 14 days after L. intracellularis challenge. Clinical signs were evaluated in 80 pigs each day for 14 days after treatment was initiated. Necropsies were performed on all pigs 14 days after treatment to evaluate gross and microscopic intestinal lesions. The challenged pigs had a positive treatment response to injectable tylosin compared with negative controls based on improvements in clinical signs, fecal polymerase chain reaction incidence on days 7 and 14, gross and microscopic intestinal lesions, average daily weight gain, and individual pig weight variation.