# Effectiveness of Medical Treatment on Survivability in Canine Cushing’s Syndrome: A Systematic Review and Meta-Analysis

## TL;DR

This study compares the effectiveness of various drugs in treating Cushing’s syndrome in dogs and finds that trilostane may improve long-term survival.

## Contribution

The study provides the first meta-analysis comparing drug treatments for Cushing’s syndrome in dogs, identifying trilostane as potentially more effective than mitotane.

## Key findings

- Trilostane showed an 11% higher survival rate at 36 months compared to mitotane.
- Other drugs like ketoconazole and cabergoline did not show significant survival benefits.
- The results suggest a need for more standardized clinical trials to confirm these findings.

## Abstract

Cushing’s syndrome is a common endocrine disorder in dogs characterized by prolonged exposure to excessive cortisol. Several pharmacological agents, including trilostane, mitotane, ketoconazole, cabergoline, selegiline, and aminoglutethimide, are used to manage the condition, but their impact on survival outcomes remains uncertain. This systematic review and meta-analysis evaluated the effects of all these treatments on survival time in dogs with naturally occurring Cushing’s syndrome. Five studies involving 295 dogs met the inclusion criteria. The results showed that trilostane may provide a long-term survival benefit compared to mitotane, with an 11% higher survival rate at 36 months (risk difference: −0.11; 95% CI: −0.15 to −0.06). Comparatively, the other pharmacological agents showed no treatment effect. These findings support trilostane as a more effective treatment option for Cushing’s syndrome in dogs compared to mitotane and underscores the need for prospective trials with standardized outcomes to strengthen the evidence base for veterinary clinical care.

Cushing’s syndrome is one of the most common endocrine disorders in dogs and is typically managed with long-term medical treatment. Several pharmacological agents are available: trilostane, mitotane, ketoconazole, cabergoline, selegiline, and aminoglutethimide, but their comparative effects on survival remain unclear. This systematic review and meta-analysis compared the impact of these agents on survival outcomes in dogs with naturally occurring diseases. A comprehensive search of MEDLINE, Embase, Web of Science, Academic Search Complete, and the Cochrane Library was conducted between 1 September 2024 to 3 January 2025. Eligible studies included dogs diagnosed with Cushing’s syndrome that reported survival outcomes for at least one of the specified treatments. Five studies (n = 295 dogs) met the inclusion criteria, with trilostane and mitotane providing sufficient data for meta-analysis. Pooled mean difference in survival time across four studies was 85.1 days (95% CI: −255.9 to 85.7, p = 0.21) with substantial heterogeneity (I2 = 89%), indicating no statistically significant difference between the drugs. In contrast, pooled survival rates at fixed intervals favored trilostane, with an 11% higher survival at 36 months (p = 0.005) and no heterogeneity observed (I2 = 0%). These findings suggest trilostane may offer long-term survival benefits over mitotane.