Hyperadrenocorticism (hac) is an endocrinological disorder characterized by an increase in glucocorticoid levels, which will progressively or suddenly induce clinical and biological signs that may vary from one individual to another. The research was carried out on 10 dogs diagnosed with HAC by dosing their basal cortisol and following synthetic adrenocorticotrope hormone (Synactene) stimulation; we used Elisa (Snap Reader-Idexx) method. Clinical and biochemical exams were performed in order to highlight potential changes. Following clinical exams we discovered the next clinical signs, ranked from most to least important: lethargy and limited tolerance to movement, muscular atrophy, myotonia, polyphagia, increased liver size, polyuria and polydipsia, abdominal distention, alopecia, cutaneous changes, reproductive disorders, cutaneous calcinosis, neurological signs. We did not record cutaneous signs in young dogs diagnosed with HAC, as it was the case with older dogs. The breeds affected were diverse with the highest occurrence in Caniche. The dogs were on average 7,6 years old (4-11 years old) and the most impacted were the male individuals (70%). The biochemical blood changes were variable and consisted of: an increase in ALT activity (by 100%), in alkaline phosphatase activity (by 90%), elevated cholesterol (by 60%), and glycemia levels (20%), hypercalcemia (by 20%). It is necessary to examine any dog, which exhibits the clinical or biological signs described by the present study for an early diagnosis of HAC in order to prevent the devastating effects of glucocorticoids