Poaching remains a primary threat to wildlife across Southeast Asia’s protected forests; however conventional ranger patrols face significant challenges detecting and intercepting poaching activity in dense tropical terrain. Tracking dogs offer a potential force multiplier for counter-poaching units, but deployment decisions have until now been made without empirical performance data from operational tropical conditions. We evaluated a tracking dog in the tropical forests of Peninsular Malaysia across three complementary study components: controlled covert-fixing of fresh signs trials (n = 100), environmental tracking trials across five track-age categories (30 minutes to 7 days; n = 23), and assessment of live counter-poaching and reconnaissance deployments (n = 9). The dog successfully fixed the target in 97 per cent of fresh scent exercises, maintaining covertness in 85 per cent of successful fixes. Success rates declined with increasing track age: 100% at 30 minutes, 75% at 8 hours, 67% at 24 hours, and 33% at 7 days. Increasing heat index was negatively associated with tracking success, with success rates declining from 78 per cent under moderate conditions to 50 per cent under high heat (>34 °C), though this trend was not statistically significant at the sample sizes available (Fisher’s Exact Test, p = 0.53). Live deployments demonstrated the dog’s capacity to detect aged campsites, rest areas and active snares under operational conditions, while also revealing practical constraints around logistics, ranger integration and handler–team coordination. This study provides the first field-based performance benchmark for an operational counter-poaching dog unit in a tropical South-East Asian forest, offering protected area managers an evidence base to guide investment and deployment decisions, and a replicable three-component evaluation framework applicable to other canine programmes.