Veterinarska stanica, Vol. 53 No. 6, 2022.
Review article
https://doi.org/10.46419/vs.53.6.9
Canine hyperadrenocorticism (Part II: Diagnostics and therapy)
Mirna Brkljačić
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Ivana Kiš
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Anđela Krizman
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Vesna Matijatko
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Gabrijela Jurkić Krsteska
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Filip Kajin
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Zoran Vrbanac
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Karol Šimonji
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Nada Kučer
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Abstract
The clinical syndrome of naturally occurring hyperadrenocorticism (HAC) in dogs is one of the most common endocrinopathies in veterinary medicine. The clinical manifestations and laboratory findings reflect the influence of a chronically increased concentration of circulating cortisol. The diagnosis is based upon a compatible history and the presence of one or more clinical signs. The greater the number of clinical symptoms and laboratory changes, the stronger the suspicion of HAC. According to a consensus in veterinary medicine, diagnostic tests should be carried out only in patients with appropriate clinical signs, results of diagnostic imaging and in patients with comorbidities not responding to adequate therapy in order to enhance the positive predictive value of endocrinological tests. None of currently available adrenal function tests are reliable due to frequent false-positive and false-negative results mainly originating from non-adrenal diseases or medications that can influence the results. The diagnostic tests for HAC are based on proving either increased production of cortisol or decreased sensitivity of the hypothalamic-pituitary-adrenal axis to negative glucocorticoid feedback. The available tests are subdivided into screening tests (ACTH-stimulation test - ACTHST, low-dose dexamethasone suppression test - LDDST, and urine corticoid-to-creatinine ratio - UCCR) and differentiating tests (endogenous ACTH concentration - eACTH, LDDST, high-dose dexamethasone suppression test - HDDST, and dexamethasone suppression with UCCR). The best diagnostic yield is achieved with a combination of adrenal function tests and diagnostic imaging (DI). All modalities of DI can be used, though the methods differ in specificity and sensitivity, much like the adrenal function tests. Suitable DI methods for adrenal diseases are ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen, while CT and MRI of the head are taken to determine pituitary diseases. Usually, abdominal ultrasound is used in combination with a screening test to establish a definitive diagnosis. To determine the optimal therapy, it is necessary to distinguish between pituitary dependent HAC (PDH) and adrenal tumours (ADH). Available treatment options are radiation, medical or surgical therapy. The surgery of the hypophysis or adrenal tumour, and radiotherapy in cases of PDH, are aimed at removing the cause of the disease, and although they are potentially curative, they are expensive, not widely available, and include inherent risks. Medical therapy consists of either the adrenocorticolytic drug mitotane or trilostane that inhibits steroidogenesis. Both medications are also expensive, are taken life-long, and have their own inherent risks. This review considers the current treatment options regarding availability, efficacy and adverse effects of therapy, while also taking into account the form and spread of the disease, and the age and comorbidities of the patient, with the goal of the selecting the most optimal treatment plan.
Keywords
hyperadrenocorticism; dog; diagnostics; therapy
Hrčak ID:
272377
URI
Publication date:
16.1.2022.
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