Accuracy of an Adrenocorticotropic Hormone (ACTH) Immunoluminometric Assay for Differentiating ACTH‐Dependent from ACTH‐Independent Hyperadrenocorticism in Dogs

Background Lowering the dose of desoxycorticosterone pivalate (DOCP) for the treatment of dogs with primary hypoadrenocorticism (PH) decreases costs and could lead to increased owner motivation to treat their affected dogs. Objective To evaluate the efficacy of a low‐dose DOCP treatment protocol in dogs with PH. Animals Prospective study, 17 client‐owned dogs with naturally occurring PH (12 newly diagnosed, 5 previously treated with fludrocortisone acetate [FC]). Methods Dogs with newly diagnosed PH were started on 1.5 mg/kg DOCP SC; dogs previously treated with FC were started on 1.0‐1.8 mg/kg DOCP SC. Reevaluations took place at regular intervals for a minimum of 3 months and included clinical examination and determination of serum sodium and potassium concentrations. The DOCP dosage was adjusted to obtain an injection interval of 28‐30 days and to keep serum electrolyte concentrations within the reference interval. Results Median (range) follow‐up was 16.2 months (4.5‐32.3 months). The starting dosage was sufficient in all but 2 dogs and had to be significantly decreased after 2‐3 months to a median dosage (range) of 1.1 mg/kg (0.7‐1.8). Dogs 3 years of age or younger needed significantly higher dosages compared to older dogs. None of them, however, needed the 2.2 mg/kg DOCP dosage, recommended by the manufacturer. Conclusions and Clinical Importance A starting dosage of 1.5 mg/kg DOCP is effective in controlling clinical signs and serum electrolyte concentrations in the majority of dogs with PH. An additional dose reduction often is needed to maintain an injection interval of 28‐30 days. Young and growing animals seem to need higher dosages.

Section: Methodsmentioning

confidence: 99%

Evaluation of a low‐dose desoxycorticosterone pivalate treatment protocol for long‐term management of dogs with primary hypoadrenocorticism

Sieber-Ruckstuhl

Reusch

Hofer‐Inteeworn

et al. 2019

“…Cases in the HAC group were defined as PDH if any of the following criteria were met: endogenous ACTH concentration > 5 pg/mL (ELISA validated for dogs [sensitivity of 0.22 pg/mL, detection limit of 5 pg/mL, intra‐assay CV of less than 6.7% and interassay CV of less than 7.1%] Nationwide Laboratories, UK), pituitary enlargement on magnetic resonance imaging (MRI) or computed tomography (CT) or bilaterally normal to enlarged adrenal glands on abdominal ultrasonography. All adrenal glands > 4 cm were considered neoplastic .…”

Section: Methodsmentioning

confidence: 99%

“…All adrenal glands > 4 cm were considered neoplastic . Functional AT was diagnosed if any of the following criteria were met: endogenous ACTH concentration < 5 pg/mL, an adrenal mass with a maximal dorsoventral thickness of the contralateral gland ≤ 5 mm 18 or histopathological confirmation of adrenocortical neoplasia associated with resolution of clinical signs of HAC after adrenalectomy. If an adrenal mass was identified but the criteria for functional AT were not fulfilled, such dogs were grouped separately.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of individual low‐dose dexamethasone suppression test patterns in naturally occurring hyperadrenocorticism in dogs

Bennaim

Shiel

Forde

et al. 2018

BackgroundDogs with hyperadrenocorticism (HAC) may be more mildly affected at the time of diagnosis today, which could influence the prevalence of associated clinical and clinicopathological abnormalities and diagnostic test performance. Different low‐dose dexamethasone suppression test (LDDST) result patterns have not been evaluated individually.ObjectivesTo assess the current features of HAC and evaluate if the diagnostic test performance of individual LDDST result patterns differ.AnimalsOne hundred and twenty‐three dogs undergoing investigation for HAC.MethodsRetrospective evaluation of dogs in which a LDDST was performed and HAC confirmed or excluded by alternative means. Cases with basal cortisol concentrations (t 0) < 1 μg/dL were excluded. Each LDDST result was classified as (a) complete suppression (t 3 and t 8 < 1 μg/dL), (b) lack of suppression (t 3 and t 8 > 1 μg/dL and both > 50% t 0), (c) partial suppression (t 3 and t 8 > 1 μg/dL but either < 50% t 0), (d) escape (t 8 > 1 μg/dL and t 3 < 1 μg/dL) or (e) inverse (t 3 > 1 μg/dL and t 8 < 1 μg/dL) pattern.ResultsFifty‐nine (48%) dogs were diagnosed with HAC and 64 (52%) with non‐adrenal illness. Hyperadrenocorticism cases had similar clinicopathological abnormalities compared to previous reports. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) (95% confidence interval [CI]) of the LDDST for diagnosing HAC were 96.6 (91.9‐100)%, 67.2 (55.7‐78.7)%, 73.1 (63.2‐82.9)%, and 95.6 (89.5‐100)%, respectively. Lack of suppression pattern had the highest PPV (93.9 [85.8‐100]%) followed by the partial suppression pattern (67.9 [50.6–85.2]%) and escape or inverse pattern (36.8 [15.1–58.5]%).Conclusions and Clinical ImportanceA lack of suppression LDDST pattern has the highest PPV for diagnosing HAC followed by a partial suppression pattern. By contrast, the escape or inverse pattern provided limited support of HAC.

“…To help in the differentiation of PDH, particularly in dogs with equivocal adrenal asymmetry on ultrasonography, the HDDST was performed (n = 30) and/or endogenous ACTH plasma concentration was determined (n = 28). PDH was diagnosed if cortisol concentration was suppressed (<50% of basal cortisol concentration at 4 or 8 hours in LDDST or HDDST) or endogenous ACTH plasma concentration was >5 pg/mL . Endogenous ACTH plasma concentrations were measured at commercial laboratories by means of a chemiluminescent enzyme immunoassay that has been validated for dogs …”

Section: Methodsmentioning

confidence: 99%

Comparison of Survival Times for Dogs with Pituitary‐Dependent Hyperadrenocorticism in a Primary‐Care Hospital: Treated with Trilostane versus Untreated

Nagata

Kojima²,

Yuki

2016

BackgroundAlthough pituitary‐dependent hyperadrenocorticism (PDH) is one of the most common endocrinopathies in dogs, the effects of withholding treatment on survival time in dogs with PDH remain unclear.Hypothesis/ObjectivesThe purpose of this study was to clarify the effects of treatment in dogs with PDH by comparing survival times between dogs treated with trilostane and untreated dogs.AnimalsForty‐three dogs diagnosed with PDH at a primary‐care hospital in Japan between June 2009 and January 2014.MethodsRetrospective cohort study. The medical records of dogs with PDH treated with trilostane (n = 17) or left untreated (n = 26) were reviewed retrospectively. Survival analysis at 2 years after diagnosis of PDH was performed.ResultsMedian survival time for the trilostane group was not reached (95% confidence interval [CI], 443 days–not applicable) and was significantly longer than the 506 days (95% CI, 292–564 days; P = .016) for the untreated group. Multivariate Cox proportional hazards analysis (including age at diagnosis, basal cortisol concentration at diagnosis, and treatment group) only identified assignment to the untreated group (hazard ratio, 5.01; 95% CI, 1.63–15.44) as associated with increased mortality.Conclusions and Clinical ImportanceThe results of this retrospective cohort study suggest that withholding treatment for dogs with PDH might be associated with a higher risk of death. This represents the largest study to date to report survival times of untreated dogs with PDH.