Diagnosis of naturally-occurring Cushing's syndrome by primary care veterinarians in selected European countries

Abstract

Background: Several tests are available to diagnose naturally-occurring Cushing'ssyndrome in dogs but there is a paucity of information on how primary careveterinarians (PCVs) use or interpret them.Objectives: Determine how PCVs from selected European countries diagnose Cush-ing's syndrome in dogs.Methods: Cross-sectional survey study assessing testing protocols used by PCVs forscreening and differentiation of Cushing's syndrome.Results: Two thousand one hundred and seventy-eight responses from 9 Europeancountries were included. When Cushing's syndrome was suspected, 98.7% of respon-dents perform endocrine testing, whereas 1.2% rely on a treatment trial. Among theformer, 59.9% reported performing screening tests in the absence of supportive clini-cal signs but with consistent clinicopathological abnormalities. Of 2150 respondentswho performed endocrine testing, 66.6% report always using the same initial screen-ing tests regardless of their pretest suspicion of disease. The tests most reported arethe ACTH stimulation test (34.8%), low-dose dexamethasone suppression test(LDDST; 30.4%) or a combination of different tests (25.2%). In the absence offinancial constraint, 1419 (66.0%) respondents always attempted differentiation,using abdominal ultrasonography (81.0%) and LDDST (46.1%). Overall, 69.8% ofrespondents reported offering referral to a specialist in ≤20% of cases suspected ordiagnosed with Cushing's syndrome over the previous 5 years.Conclusions and Clinical Importance: Testing protocols vary among PCVs. Almost60% of respondents potentially screen dogs without consistent clinical signs, raisingconcerns for overdiagnosis. A proportion never attempt differentiation, which likelyaffects prognosis. Cases are rarely referred to a specialist, reflecting that Cushing'sAbbreviations: ACTHst, adrenocorticotropic hormone stimulation test; ADH, adrenal-dependent hypercortisolism; AUS, abdominal ultrasound; CT, computed tomography; HDDST, high-dosedexamethasone suppression test; IQR, interquartile range; LDDST, low-dose dexamethasone suppression test; MRI, magnetic resonance imaging; PCVs, primary care veterinarians; PDH,pituitary-dependent hypercortisolism; RI, reference interval; SBP, systemic blood pressure; UCCR, urine corticoid-to-creatinine ratio; UCCRDST, UCCR dexamethasone suppression test.Received: 18 December 2023 Accepted: 31 July 2024DOI: 10.1111/jvim.17166This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in anymedium, provided the original work is properly cited and is not used for commercial purposes.© 2024 The Author(s). Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.J Vet Intern Med. 2024;1–9. wileyonlinelibrary.com/journal/jvim 1