Conduta diagnóstica em equino da raça Crioula com síndrome de Cushing / Diagnostic process in a crioulo horse with Cushing’s syndrome

ABSTRACT

Background: Equine pituitary pars intermedia dysfunction, also known as equine Cushing’s syndrome, is a neurodegenerative disease. An important risk factor for Cushing’s is advanced aging and it is the most common endocrine disorder inolder horses. The prevalence in horses aged over 10 and 15 years is reported as 9.3% and 21%, respectively. Due to the slowprogressive nature of the disease, seasonal variation in hormone output and overlapping endocrine response to other events,accurate diagnosis is challenging. The diagnosis requires the combination of anamnesis, clinical signs, in addition to laboratory tests results. This study aimed to report Cushing’s syndrome in a Crioulo breed horse focusing on diagnostic methods.Case A 13-year-old male Crioulo breed, orchiectomized, was attended at the Universidade de Passo Fundo (UPF), in PassoFundo, RS, Brazil. The owner reported that the animal had progressive weight loss and coat abnormal growth, with curlyappearance. From visual inspection, body condition score was 4 (1-9) bulging abdomen was noticed, hirsutism, depressionand lethargy. Also, there was a large neoplastic mass on the left side of gluteal region. Later, this mass was classified inhistopathological examination as a fibroblastic sarcoid and was treated. The animal presented physical parameters withinthe physiological limits of the specie. Normochromic normocytic anemia and neutrophilic leukocytosis were reported in thehematologic evaluation. In coproparasitological examination, there were 300 eggs per gram of feaces. Hyperadrenocorticismwas suspected in the clinical examination and dexamethasone suppression test was performed to confirm the fact. Basal serumwas collected at 17 h (M0) and subsequently 40 µg/kg of dexamethasone was administered intramuscular...