Acromegalia em felinos

Abstract

Acromegaly in felines occurs mainly due to a pituitary adenoma of somatotropic cells, and presents slow and progressive evolution, responsible for increasing the production and secretion of growth hormones (GH). This condition is common in senile or adult male domestic cats, neutered and with short hair. The pathophysiology is due to the excessive release of GH in the adenohypophysis region, whose synthesis is regulated by growth hormone-releasing hormone (GHRH) and somatostatin, responsible for stimulating or inhibiting the secretory axis, respectively. The anabolic action of GH is responsible for increasing the secretion of IGF-1, which is mainly responsible for the clinical signs of acromegaly, such as body growth and organomegaly. The catabolic effect refers to insulin resistance. Clinical signs may be associated with secondary diabetes mellitus (DM), weight gain, exacerbated growth of various tissues and neurological signs as the tumor mass grows. The diagnosis of the disease can be performed through laboratory, imaging and endocrine tests such as the specific immunoassay for GH and/or insulin-like growth factor 1 (IGF-1). Treatment is based on controlling the DM that develops secondary to it, as well as on attempts to reduce or even inhibit the excess release of GH. Treatment can be performed with somatostatin analogues and dopamine agonists. The use of stereotactic radiotherapy can also be recommended, with favorable results for tumor reduction, as well as the surgical technique of transsphenoidal hypophysectomy, which presents better results than other techniques but is a complex surgical procedure. This project aims to inform veterinarians of this endocrine disease and its main currently recognized diagnoses and treatments, emphasizing the need to establish a differential diagnosis for difficult-to-control DM.