Trilostane is primarily used in the treatment of Cushing's disease (hyperadrenocorticism) in dogs. It works by inhibiting an enzyme involved in steroid hormone production, thereby reducing the excessive levels of cortisol produced by the adrenal glands. This helps manage symptoms such as increased thirst, urination, appetite, and abdominal enlargement. It is also used off-label in some cases to manage adrenal tumors or atypical Cushing's syndrome. In veterinary medicine, trilostane is preferred over older treatments due to its reversible action and relatively safer profile when monitored appropriately. Regular blood testing is required to ensure proper dosage and to avoid adrenal insufficiency.