In today's VETgirl online veterinary continuing education podcast, we review two different protocols for trilostane administration in dogs with pituitary-dependent hyperadrenocorticism (PDH). Hyperadrenocorticism, or Cushing's disease, is one of the most common endocrinopathies of dogs. As you all may remember, naturally occurring Cushing's disease comes in two flavors: pituitary-dependent or adrenal-dependent. Approximately 85% of dogs with Cushing's disease have the pituitary-dependent form (Feldman). While a number of treatment strategies are available, trilostane has become an increasingly popular and effective first-line therapy (Alenza). Trilostane is a competitive inhibitor of 3B-hydroxysteroid dehydrogenase (Potts). Personally, I need a translation for what on earth that means! Basically trilostane inhibits an enzyme essential to the synthesis of both glucocorticoids and mineralocorticoids in the adrenal cortex. The manufacturer recommends a trilostane starting dose of 2.2-6.7 mg/kg/day. So, Cho et al wanted to evaluate this in a study entitled Efficacy of Low- and High-Dose Trilostane Treatment in Dogs (<5 kg) with Pituitary-Dependent Hyperadrenocorticism. In this study, the safety and efficacy of two alternative protocols of trilostane administration were evaluated in dogs with PDH. The first was a twice-daily low-dose protocol, and the second was a once-daily high-dose protocol.