Effects of phenylbutazone and anabolic steroids on adrenal and thyroid gland function tests in healthy horses.

This research study explored how short-term therapies using phenylbutazone, stanozolol, and boldenone undecylenate affect adrenal and thyroid functions in healthy horses. The study determined that there were no significant effects of these treatments on mean basal plasma cortisol or thyroxine concentrations.

Objective of the Study

• The main focus of this research was to determine the effects of phenylbutazone and anabolic steroids namely stanozolol, and boldenone undecylenate on the function of adrenal and thyroid glands in healthy horses.

Study Design

• Adrenal and/or thyroid gland functions were evaluated at different times during the short-term therapy involving phenylbutazone, stanozolol, and boldenone undecylenate.
• The phenylbutazone was given twice daily (4 to 5 mg/kg, IV) for 5 days; stanozolol, was administered twice weekly (0.55 mg/kg, IM) for 12 days while boldenone undecylenate was given twice weekly (1.1 mg/kg, IM) for 12 days.

Study Findings

• The research found that there were no significant effects on mean basal plasma cortisol concentrations during the treatment period with either of the drugs tested.
• In the case of phenylbutazone, there was no significant change in plasma cortisol concentration during the combined dexamethasone-suppression adrenocorticotropic hormone (ACTH)-stimulation test.
• The research found that plasma cortisol concentrations decreased significantly from base line at 3 hours after dexamethasone was given, and increased significantly from the base line at 2 hours after ACTH treatment in horses.
• However, this was not affected by treatment with either stanozolol or boldenone undecylenate.
• The study also found no significant effects on mean basal plasma concentrations of thyroxine (T4) or triiodothyronine (T3) among horses during the treatment period.

Conclusion

• Overall, the study concluded there is no significant impact of short-term therapy with phenylbutazone, stanozolol and boldenone undecylenate on the adrenal and thyroid gland function in horses.