The initial phase of the Cobalt Pilot Research Project, funded by the Ohio State Racing Commission and conducted at The Ohio State University College of Veterinary Medicine, has been completed.
The goals of the study were to assess the physiologic, biochemical and endocrine effects of repeated doses of intravenous cobalt chloride in five Standardbred mares and to investigate the pharmacokinetics of cobalt over a three-month period. Each horse received one of five different doses of cobalt chloride (0.25, 0.5, 1, 2 and 4 mg/kg) weekly for five weeks.
A research summary (Intravenous administration of cobalt chloride is associated with hemodynamic alterations in horses by Teresa Burns, Turi Aarnes, Jeffrey Lakritz, Ramiro Toribio) was presented at the 2016 American College of Internal Veterinary Medicine meeting on June 9 in Denver, Colo.
This research documents that cobalt chloride administered intravenously causes horses to become anxious and, at higher doses, to show muscular tremors, pawing and signs of abdominal discomfort. Cardiac arrhythmias, tachycardia, central and peripheral arterial hypertension and renal dysfunction were consistently noted.
A transient increase in hematocrit and red blood cell count was noted, however, changes in erythropoietin concentrations or changes in erythropoiesis or red blood cell numbers were not seen during the study period.
Baseline plasma cobalt levels in the subject horses were 3.6 ± 3.1 ppb (parts per billion). The plasma half-life of cobalt for all horses in this study was 12 ± 1.4 days and the time required for cobalt to be below 25 ppb ranged from 40 days (0.25 mg/kg dose) to 90 days (4 mg/kg dose).
Laboratory and data analyses are ongoing, specifically: measurement of urine cobalt concentrations to further investigate pharmacokinetics of cobalt and measurement of endocrine variables and markers that may be linked to performance.
Regardless of what further research may show regarding the effects of elevated levels of blood cobalt on performance, the initial findings of this research prove that cobalt chloride administered intravenously can be harmful to horses.
(Ohio Standardbred Development Fund )