The objective of this research was to investigate and evaluate the diagnostic methods used for hyperadrenocorticism in dogs by analyzing the available literature from the past 20 years. The methodology employed was a qualitative and exploratory literature review, conducted through databases such as PUBMED, MEDLINE, BVS, SCOPUS, PERIÓDICOS, BIBLIOTECA ABERTA USP, and SCIELO. Keywords such as "dogs," "canine," "hyperadrenocorticism," "endocrine," "endocrinopathy," and "Cushing" were used to identify relevant studies. The content analysis of the selected articles revealed that diagnostic methods vary according to the clinical suspicion and include detailed anamnesis, thorough clinical examination, and basic and imaging laboratory tests. The choice between suppression and stimulation hormone tests depends on the suspected origin of the condition, with the low-dose dexamethasone suppression test being highly sensitive for detecting hyperadrenocorticism, while the ACTH stimulation test is crucial for differentiating between origins. Diagnostic confirmation also involves abdominal ultrasonography to visualize the adrenal glands and identify possible masses, which is essential for guiding appropriate treatment and determining the patient’s prognosis.