title: Azithromycin in the treatment of pneumonic foals.
abstract: Rhodococcus equi, one of the most common causes of pneumonia in foals between 3 weeks and 5 months of age, is a troublesome disease. For many years, Rhodococcus equi pneumonia carried a very poor to grave prognosis due to the lack of a good treatment protocol. However, antibiotics that are very good at treating the infection have been identified. Through research we have begun to further understand the epidemiology of the disease, acquired an arsenal of suitabe treatment options, and identified prevention strategies that are actively being studied. Oral erythromycin requires multiple daily dosing, has inconsistent absorption rates in foals, and a growing number of resistant Rhodococcus equi isolates have been identified. Azithromycin and clarithromycin have been proposed as alternatives to erythromycin for the treatment of Rhodococcus equi. Studies in other species have demonstated that azithromycin has better pharmacokinetics and is safer than erythromycin. Azithromycin has shown high and sustained intracellular and tissue concentrations with levels still high 48 hours after administation of the last oral dose. Azithromycin is commercially available in 250-mg and 500-mg tablets, and 100-mg/5 mL and 200-mg/5-mL oral suspensions. Oral pastes and powder feed additives in various concentrations and flavors can be formulated by compounding pharmacists.
authors: Walgreen Drug Stores, West Plains, Missouri.
authors: Bethany L
authors: BL
authors: Bramwell
authors: Lavonn A
authors: LA
authors: Williams