Alternative antimicrobial agents in the treatment of proliferative enteropathy in horses

Seven young horses 5 to 12 months old, each diagnosed with proliferative enteropathy, were studied. All seven cases responded to alternative antimicrobial therapy to the traditional treatment of erythromycin ± rifampin. Three cases were treated with chloramphenicol, two cases with doxycycline, one with azithromycin, and one with clarithromycin and rifampin. All showed resolution of clinical and clinicopathological abnormalities within 8 weeks of initiation of treatment. Proliferative enteropathy is an increasingly recognized malabsorptive and maldigestive disease of young horses. Supportive care and antimicrobial therapy are the mainstays of therapy with erythromycin being the traditional antibiotic of choice. The knowledge that alternative therapeutic antimicrobials are clinically efficacious in the treatment of Lawsonia intracellularis broadens the therapeutic options for this potentially fatal condition.