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Efficacy and safety of tightly controlled hyperadrenocorticism in dogs treated with trilostane in general practice

Foster, S., Fleeman, L.M., Langner, K.F.A. and Braddock, J.A. (2020) Efficacy and safety of tightly controlled hyperadrenocorticism in dogs treated with trilostane in general practice. Journal of Veterinary Internal Medicine, 34 (6). pp. 3058-3166.

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There is no agreement about ideal control of hyperadrenocorticism in dogs treated with trilostane. Many veterinarians select sub‐optimal control of hyperadrenocorticism to limit the possibility of clinical hypoadrenocorticism. The aim of this study was to assess clinical responses in dogs treated in general practice with tight control as defined by an ACTH‐stimulated cortisol concentration of <70 nmol/L (Advia Centaur) when test performed 4‐6h after trilostane.

Between August 2017 and February 2019, dogs with confirmed hyperadrenocorticism that had a minimum 12 month period of tight control were identified. Owners were provided with a published questionnaire relating to the period(s) of tight control. Data from the laboratory submissions and owner questionnaires were analysed for age, sex, breed, duration of treatment, duration of tight control, adverse effects and clinical scores. For each period of tight control, the percentage of basal and ACTH‐stimulated cortisols within the following a priori categories were determined: <14, 14‐29 nmol/L.

There were 44 periods of tight control in 43 dogs. Age at end of tight control was 5.5‐17.5 years (median 12.5). All dogs were neutered (23 female, 20 male). Twenty five (58%) were purebred dogs and 11 (25%) were Maltese dogs and their crosses. Tight control period ranged from 12‐36 months (median 19). Total treatment time was 16‐60 months (median 30). Median survival time was not reached. Dogs were treated once daily (32), twice daily (10) both (1) or other (1). Mean interval between ACTH stimulation tests was 3.8 months. Twenty four percent (51/216) and 46% (100/216) basal cortisols were <14 and <30 nmol/L respectively. Six percent (15/269) and 36% (98/269) post‐stimulation cortisols were <14 and <30 nmol/L respectively. There was no association between frequency of “sickness or diarrhea” and dogs’ percentages of results <14 or 14‐29 nmol/L.

Clinical score was excellent (4‐11) in 28, reasonable (12‐16) in 13 and poor (>17) in 2; median score 10. Median scores for drinking, urinating, appetite and skin/coat were 1 (normal). Median score for general assessment was 2 and median score for exercise was 3. Clinical score was impacted by the exercise assessment which many owners considered unrelated to hyperadrenocorticism or its treatment.

Tight control of hyperadrenocorticism assessed by an ACTH stimulation test 4‐6h after trilostane resulted in excellent clinical scores in most dogs. Tight control did not impact negatively on dogs’ health. An ACTH‐stimulated cortisol of 30‐70 nmol/L on this assay appears a safe and efficacious monitoring goal in general practice.

Item Type: Journal Article
Murdoch Affiliation(s): College of Science, Health, Engineering and Education
Publisher: Wiley-Blackwell
Copyright: © 2020 The Authors.
Other Information: Oral abstract given @ RESEARCH COMMUNICATIONS OF THE 30th ECVIM‐CA ONLINE CONGRESS 2‐5 September 2020
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