2016 ACVIM Forum Research Abstract Program

After the last dose, the mean + SD maximum plasma concentration (Cmax) of minocycline was 2.3 + 1.3 µg/mL and the terminal half-life (T1/2) was 11.8 + 0.5 hours. The median (25th and 75th percentiles) time to peak concentration (Tmax) was 1.3 (1.0 -1.5) hrs. The Cmax and Tmax of minocycline in the PELF were 10.5 + 12.8 µg/mL and 9.0 (5.5 -12.0) hrs, respectively. The Cmax and Tmax for BAL cells were 0.24 + 0.1 µg/mL and 6.0 (0.0 -6.0) hrs, respectively. Peak and trough minocycline concentrations in PELF were significantly higher than in plasma whereas concentrations in BAL cells were significantly lower. Orally administered minocycline distributes into the PELF and BAL cells of the horse. Knowledge of specific minimum inhibitory concentrations is required to predict efficacy of minocycline for the treatment of bacterial pneumonia in adult horses. Cobalt is a substance of abuse in humans and animals performing in strenuous athletic competitions. When administered at pharmacologic doses, it has been associated with induction of erythropoietin release, increased hematopoiesis, which is thought to confer competitive advantage. Cobalt chloride (CoCl 2 ) is reportedly given to racehorses to enhance performance, and recently, allowable limits for cobalt have been set by several racing jurisdictions for post-race illicit substance testing of blood and urine. While preliminary single-dose pharmacokinetic data have been published for CoCl 2 in horses, information regarding the effects of repeated dosing (which is how the substance is reportedly used illicitly in performance horses) is unavailable. Even fewer data have been published describing the pharmacodynamic effects of CoCl 2 administration in horses, particularly at high doses. The purpose of this pilot study was to describe the physiologic and biochemical effects of weekly intravenous doses of CoCl 2 to Standardbred horses. This report describes the hemodynamic effects of CoCl 2 in a dose escalation study.