Survival analysis of 219 dogs with hyperadrenocorticism attending primary care practice in England.

BACKGROUND: Hyperadrenocorticism is an endocrine disease routinely encountered within primary care practice; however, few studies evaluating survival beyond diagnosis have studied this population. METHODS: This retrospective cohort study analysed the electronic patient records of 219 cases of hyperadrenocorticism from a sample of dogs attending primary care practices in England. Kaplan-Meier plots examined the cumulative survival and Cox proportional hazard regression modelling identified factors associated with the hazard of all-cause mortality. RESULTS: In the analysis, 179/219 (81.7 per cent) hyperadrenocorticism cases died during the study period with a median survival time from first diagnosis of 510 days (95% CI 412 to 618 days). Trilostane was used in 94.1 per cent of cases and differentiation between pituitary-dependent and adrenal-dependent disease was made in 20.1 per cent of cases. In the multivariable analysis, dogs weighing greater than or equal to 15 kg (HR 1.51, 95% CI 1.06 to 2.15, P=0.023) and those diagnosed greater than or equal to 13 years of age (HR 3.74, 95% CI 2.29 to 6.09, P<0.001) had increased hazards of all-cause mortality. Dogs that had their initial trilostane dose increased had a favourable prognosis (HR 0.49, 95% CI 0.32 to 0.76, P=0.015). CONCLUSION: This study shows that survival from diagnosis of hyperadrenocorticism appears fair for many dogs and provides primary care practitioners with relatable benchmark prognostic figures.

Canine hyperadrenocorticism associations with signalment, selected comorbidities and mortality within North American veterinary teaching hospitals.

OBJECTIVE: To describe a large population of dogs with a diagnosis of hyperadrenocorticism at the time of death in North American veterinary teaching hospitals, and to identify comorbid conditions associated with hyperadrenocorticism. MATERIALS AND METHODS: Retrospective cohort study of 1519 dogs with hyperadrenocorticism from a population of 70,574 dogs reported to the Veterinary Medical Database. Signalment, presence or absence of hyperadrenocorticism, aetiology of hyperadrenocorticism (if described), frequency of select comorbidities and causes of death were evaluated in dogs with and without hyperadrenocorticism. RESULTS: Hyperadrenocorticism was more frequent in females. Neutering was associated with a minor, but significant, increase in the odds of hyperadrenocorticism. Hyperadrenocorticism was the presumed cause of death of 393 (25∙9%) of affected dogs. When aetiology was specified (527 dogs, corresponding to 34∙7% of the cases), pituitary-dependent hyperadrenocorticism [387 (73∙4%) out of 527 dogs] was more common than functional adrenocortical tumour [136 (25∙8%) out of 527 dogs). Hyperadrenocorticism was over-represented in certain expected (miniature poodle, dachshund) and unexpected (Irish setter, bassett hound) breeds compared with the population at large. Of the select comorbidities investigated, dogs with hyperadrenocorticism were at increased risk for concurrent diabetes mellitus, urinary tract infection, urolithiasis, hypertension, gall bladder mucocoele and thromboembolic disease compared with dogs without hyperadrenocorticism. CLINICAL SIGNIFICANCE: Hyperadrenocorticism is significantly associated with certain comorbid conditions but is not a major cause of mortality in affected dogs. Documented patterns now provide targets for prospective clinical research.

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

BACKGROUND: Although 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/OBJECTIVES: The 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. ANIMALS: Forty-three dogs diagnosed with PDH at a primary-care hospital in Japan between June 2009 and January 2014. METHODS: Retrospective 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. RESULTS: Median 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 IMPORTANCE: The 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.

Long-term survival of dogs with adrenal-dependent hyperadrenocorticism: a comparison between mitotane and twice daily trilostane treatment.

BACKGROUND: Treatment of adrenal-dependent hyperadrenocorticism (ADH) involves either surgical resection of the adrenal tumor or medical therapy. For many years, mitotane has been considered the medical treatment of choice for dogs with ADH. OBJECTIVES: The aim of this study was to determine survival and prognostic factors for dogs with ADH treated with mitotane and trilostane. ANIMALS: Twenty-six dogs with ADH were included in the study. METHODS: Fourteen dogs were treated with mitotane and 12 dogs were treated with trilostane. Medical records were reviewed. Epidemiologic factors, signalment, clinicopathologic abnormalities, endocrine test results, and treatment protocols were evaluated to identify potential predictive factors of overall survival time. RESULTS: Survival times of dogs treated with mitotane (median, 15.6 months) or trilostane (median, 14.0 months) were not significantly different. Using univariate analysis, age and postadrenocorticotropic hormone cortisol concentrations were inversely correlated with survival time. The multivariate model also identified weakness at presentation as a negative prognostic indicator. CONCLUSION AND CLINICAL IMPORTANCE: The type of medical treatment (mitotane versus trilostane) does not influence survival time in dogs with ADH; therefore, trilostane, a drug with less frequent and milder adverse effects, might be used as the primary medical treatment when adrenalectomy cannot be performed.

A comparison of factors that influence survival in dogs with adrenal-dependent hyperadrenocorticism treated with mitotane or trilostane.

BACKGROUND: Trilostane is a recognized treatment for canine pituitary-dependent hyperadrenocorticism (PDH); however, its efficacy in dogs with adrenal-dependent hyperadrenocorticism (ADH) is unknown. OBJECTIVES: To examine factors that might influence survival in the medical management of ADH, with particular emphasis on treatment selection. ANIMALS: Thirty-seven animals referred to 4 centers over a period of 12 years that had been diagnosed with ADH and treated with either trilostane (22/37), mitotane (13/37), or both (2/37). METHODS: Retrospective analysis of clinical records. RESULTS: There was no statistically significant difference between the survival times of 13 dogs treated only with mitotane when compared with 22 dogs treated only with trilostane. The median survival time for animals treated with trilostane was 353 days (95% confidence interval [CI] 95-528 days), whereas it was 102 days (95% CI 43-277 days) for mitotane. Metastatic disease was detected in 8 of 37 dogs. There was a significantly lower probability of survival for dogs with metastatic disease when compared with those without metastatic disease (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The choice of medical treatment for ADH may not have a major effect on survival times. However, the presence of metastatic disease considerably decreases survival time regardless of the choice of medical treatment.

Use of ketoconazole to treat dogs with pituitary-dependent hyperadrenocorticism: 48 cases (1994-2007).

OBJECTIVE: To evaluate the effectiveness of ketoconazole as a treatment for dogs with pituitary-dependent hyperadrenocorticism (PDH). DESIGN: Retrospective case series. ANIMALS: 48 client-owned dogs in which PDH was diagnosed. PROCEDURES: Medical records of dogs with PDH that were treated with ketoconazole were examined. Data collected from each record included signalment, clinical signs, results of ACTH stimulation tests before and after treatment with ketoconazole, serum alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activities, dosage of ketoconazole, clinical response, and survival time. RESULTS: 43 of 48 (90%) dogs had evidence of clinical improvement during the treatment period. In all dogs, treatment with ketoconazole resulted in significantly lower serum cortisol concentrations as measured before and after ACTH stimulation testing; 69% (33/48) of serum cortisol concentrations measured after ACTH stimulation were within the reference range. Serum ALP and ALT activities significantly decreased after treatment with ketoconazole. Survival time after diagnosis of PDH ranged from 2 to 61 months (mean, 26.9 months; median, 25 months). CONCLUSIONS AND CLINICAL RELEVANCE: Ketoconazole was a safe and effective option for treating dogs with PDH. Additional research is needed to evaluate the effects of long-term treatment with ketoconazole on adrenal glands.

Comparison of non-selective adrenocorticolysis with mitotane or trilostane for the treatment of dogs with pituitary-dependent hyperadrenocorticism.

Forty-six dogs with pituitary-dependent hyperadrenocorticism were treated with mitotane by the non-selective adrenocorticolysis protocol and 40 were treated twice a day with trilostane. The treatment groups were compared by chi-squared tests, and survival data were analysed using Kaplan-Meier survival plots and a Cox proportional hazard method. The non-selective adrenocorticolysis protocol was very effective (89 per cent), its toxicity was moderate (24 per cent) and there were fewer recurrences (29 per cent) than reported with the classical selective adrenocorticolysis protocol (58 per cent). In a multivariate model, age and bodyweight at diagnosis were significantly negatively correlated with survival time. The median survival time of the dogs treated with trilostane twice a day (900 days) was longer (P=0.05) than that of the dogs treated with mitotane (720 days).

Prognostic factors for outcome after transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism.

OBJECT: The aim of this study was to determine prognostic factors for outcome after transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism (PDH). METHODS: One veterinary neurosurgeon performed transsphenoidal hypophysectomies in 181 dogs with PDH over a 12-year period. Survival analysis was performed with the Kaplan-Meier method. Prognostic factors were analyzed with the univariate Cox proportional hazard analysis followed by stepwise multivariate analysis. The log-rank test was used to assess disease-free fractions in three groups categorized according to early postoperative urinary corticoid/creatinine (C/C) ratios. RESULTS: Multivariate analysis revealed that old age, large pituitary size, and high preoperative concentrations of plasma adrenocorticotropic hormone were associated with an increased risk of PDH-related death. In addition, large pituitary size, thick sphenoid bone, high C/C ratio, and high concentration of plasma alpha-melanocyte-stimulating hormone (alpha-MSH) before surgery were associated with an increased risk of disease recurrence in the dogs that went into remission after hypophysectomy. Disease-free fractions were significantly higher in dogs with postoperative urinary C/C ratios in the lower normal range (< 5 x 10(-6)) than in dogs with postoperative C/C ratios in the upper normal range (5-10 x 10(-6)). CONCLUSIONS: The results of this study indicate that pituitary size, sphenoid bone thickness, plasma alpha-MSH concentration, and preoperative level of urinary cortisol excretion are predictors of long-term remission after transsphenoidal hypophysectomy for PDH in dogs. Urinary C/C ratios measured 6 to 10 weeks after surgery can be used as a guide for predicting the risk of tumor recurrence.

Long-term efficacy of trilostane administered twice daily in dogs with pituitary-dependent hyperadrenocorticism.

Trilostane is considered an efficacious and safe medication for canine pituitary-dependent hyperadrenocorticism (PDH). Its recommended frequency of administration is once daily. In this prospective study, the efficacy, toxicity, and long-term outcome of trilostane administered twice daily per os were evaluated in 44 dogs with PDH. Mean initial dose was 3.1 mg/kg q 12 hours, and mean final dose was 3.2 mg/kg q 12 hours. The final total daily dose was lower than previously reported for once-daily administration. The mean survival time for affected dogs was 930 days.

A comparison of the survival times of dogs treated with mitotane or trilostane for pituitary-dependent hyperadrenocorticism.

The survival times of 148 dogs treated for pituitary-dependent hyperadrenocorticism were studied using clinical records from 3 UK veterinary centers between 1998 and 2003. Of these animals, 123 (83.1%) were treated with trilostane, while 25 (16.9%) were treated with mitotane. Treatment groups were compared using t-tests and analysis of variance (or their nonparametric equivalents) and chi-square tests. Survival data were analyzed using Kaplan-Meier survival plots and Cox proportional hazard methods. There was no significant difference between the population attributes from each center or between treatment groups. The median survival time for animals treated with trilostane was 662 days (range 8-1,971) and for mitotane it was 708 days (range 33-1,399). There were no significant differences between the survival times for animals treated with trilostane and those treated with mitotane. In the multivariable model (including drug, center, breed group, weight, diagnostic group, and age at diagnosis), only age at diagnosis and weight were significantly negatively associated with survival. Importantly, there was no significant effect of drug choice on survival.

Efficacy of transsphenoidal hypophysectomy in treatment of dogs with pituitary-dependent hyperadrenocorticism.

The long-term survival, disease-free fractions, and the complications of hypophysectomy in 150 dogs with pituitary-dependent hyperadrenocorticism (PDH) were examined in a prospective study. Long-term survival and disease-free fractions in relation to pituitary size were analyzed by the Kaplan-Meijer estimate procedure. The 1-, 2-, 3-, and 4-year estimated survival rates were 84% (95% confidence interval [CI], 76-89%), 76% (67-83%), 72% (62-79%), and 68% (55-77%), respectively. Treatment failures included procedure-related mortalities (12 dogs) and incomplete hypophysectomies (9 dogs). The 1-, 2-, 3-, and 4-year estimated relapse-free fractions were 88% (CI: 80-93%), 75% (64-83%), 66% (54-76%), and 58% (45-70%), respectively. Postoperative reduction of tear production (58 eyes in 47 dogs) was often reversible but remained low until death in 11 eyes of 10 dogs. Central diabetes insipidus (CDI) occurred more frequently (62%) in dogs with enlarged pituitaries than in dogs with nonenlarged pituitaries (44%). Survival and disease-free fractions after hypophysectomy were markedly higher in dogs with nonenlarged pituitaries than in dogs with enlarged pituitaries. Transsphenoidal hypophysectomy is an effective treatment for PDH in dogs. The survival and disease-free fractions after hypophysectomy decrease and the incidence of CDI increases with increasing pituitary size. Therefore, early diagnosis of PDH is important and transsphenoidal hypophysectomy is expected to have the best outcome when used as primary treatment for dogs with nonenlarged or moderately enlarged pituitaries.

Adrenalectomy for treatment of hyperadrenocorticism in cats: 10 cases (1988-1992).

Outcome of and complications associated with bilateral adrenalectomy in 8 cats with pituitary-dependent hyperadrenocorticism and bilateral adrenocortical hyperplasia and outcome of and complications associated with unilateral adrenalectomy in 2 cats with adrenocortical tumor (adrenocortical adenoma, 1 cat; adrenocortical carcinoma, 1 cat) and unilateral adrenomegaly were determined. Glucocorticoids were administered to all cats at the time of surgery, and mineralocorticoids were administered to the 8 cats that underwent bilateral adrenalectomy. A ventral midline celiotomy was performed in all cats. Intraoperative complications did not develop in any cat. Postoperative complications developed in all cats and included abnormal serum electrolyte concentrations (n = 8), skin lacerations (n = 5), pancreatitis (n = 3), hypoglycemia (n = 2), pneumonia (n = 1), and venous thrombosis (n = 1). Three cats died within 5 weeks after surgery of complications associated with sepsis (n = 2) or thromboembolism (n = 1). Clinical signs and physical abnormalities caused by hyperadrenocorticism resolved in the remaining 7 cats 2 to 4 months after adrenalectomy. Insulin treatment was discontinued in 4 of 6 cats with diabetes mellitus. Median survival time for these 7 cats was 12 months (range, 3 to > 30 months). Two cats died of acute adrenocortical insufficiency 3 and 6 months after bilateral adrenalectomy, 2 cats were euthanatized because of chronic renal failure 3 and 12 months after bilateral (n = 1) or unilateral (n = 1) adrenalectomy, and 2 cats were alive 9 and 14 months after bilateral adrenalectomy. In the remaining cat, clinical signs recurred 10 months after the cat had undergone unilateral adrenalectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of ACTH stimulation tests to monitor the treatment of canine hyperadrenocorticism.

The case histories of 60 dogs with hyperadrenocorticism were reviewed. Fifty-four of the dogs were treated with mitotane at a mean daily dose rate of 48.8 mg/kg (range 25.6 to 84 mg/kg) for between four and 21 days. The mean weekly maintenance dose of mitotane was 48.8 mg/kg. An adrenocorticotrophic hormone (ACTH) stimulation test was performed before the treatment began, and in 30 cases at the end of the induction course, and the response to ACTH was measured at regular intervals thereafter. Nine of the treated dogs developed complete hypoadrenocorticism during treatment and required permanent mineralocorticoid replacement therapy. Twelve of the dogs had normal responses to an ACTH stimulation test before treatment, and the diagnosis of hyperadrenocorticism was based on the result of a low-dose dexamethasone suppression test. These 12 dogs had consistently lower cortisol levels before and after stimulation with ACTH and four of them developed complete hypoadrenocorticism. In general the clinical signs were well controlled when the cortisol levels were less than 105 nmol/litre before and after the stimulation test. Dogs in which the clinical signs recurred had cortisol levels between 210 and 580 nmol/litre after the test, a level which is within the normal pretreatment range. Twenty-seven of the treated dogs died and six of these deaths were attributable directly to the disease or therapy. The median survival time of the 54 treated dogs was 30 months; eight dogs died during the first 16 weeks of treatment, and the dogs which survived this period had a median survival time of 39 months (mean 50 months).