New insights on clinical features, clinicopathological abnormalities, diagnosis, treatment, and monitoring of canine Cushing’s Syndrome

The thesis explores various facets of canine hypercortisolism (HC), commonly known as Cushing's syndrome, which affects 1-2 cases per 1000 dogs annually. Initially, it provides a comprehensive overview covering clinical manifestations, diagnostic methods, and treatment options for HC. A particular focus is given to severe muscle stiffness (SMS), a poorly understood clinical sign associated with HC, with an in-depth analysis of a cohort experiencing both HC and SMS, revealing it as a rare condition affecting only dogs with pituitary-dependent hypercortisolism (PDH)without impacting life expectancy. Furthermore, the thesis investigates the relationship between HC and calcium homeostasis, uncovering elevated phosphate levels and parathyroid hormone concentrations in dogs with HC, affirming cortisol's impact on calcium balance. Diagnostic challenges in HC are highlighted due to the lack of a gold standard test, often resulting in false-positive or false-negative results. A survey among Western European primary care veterinarians reveals varying diagnostic approaches, raising concerns about potential overdiagnosis and lack of differentiation among cases, emphasizing the need for improved education in the field. Trilostane emerges as the preferred medical treatment for PDH, with ongoing debates regarding monitoring methods. While trilostane effectively manages most cases, a portion of dogs does not respond positively, with factors such as alopecia and ultrasound-detected adrenomegaly associated with poor response. The thesis also delves into alternative pituitary drug therapies targeting dopamine receptors, with cabergoline showing promise in inhibiting pituitary tumor growth when associated with trilostane. Overall, the thesis provides a multifaceted examination of HC in dogs, addressing clinical, diagnostic, therapeutic, and prognostic aspects while shedding light on the complexities and challenges involved in its management.