The modern cynological service of Ukraine is an integral part of the National Police of Ukraine, the National Guard of Ukraine, the State Border Guard Service, the State Emergency Service of Ukraine. The purpose of this study was to shed light on the history of cynology. To address this issue, the task was to collect and systematize data on the development of cynology. The main purpose of dog training in the law enforcement system is primarily to assist employees of these structures in improving the effectiveness of their activities to prevent, stop, detect and investigate crimes, using the special knowledge of dog handlers, as well as their skillful use of service dogs as a special means. The following research methods were used in the research process: general scientific – logical analysis, generalization, classification, systematization, actualization and comparison; historical – biographical, problem-chronological, comparative-historical. The history of the human-dog relationship dates back more than 500,000 years. Archival documents contain records of the use of dogs in military affairs more than 6,000 years ago in Eurasia, Africa and North America. As early as 7000 BC, purposeful dog breeding was widespread. No other animal species shows such diversity. Today there are more than 400 breeds of dogs, not counting crossbreeds. Despite this biodiversity, all domestic dogs belong to the same family, the Canis familiis, whose wild ancestor is the wolf, as evidenced by DNA analysis. To date, there are three main areas of dog breeding: service, which includes herding, associated with various branches of animal husbandry, riding (harness) and own service – the use of dogs for guard, search and other services; hunting (industrial and sports); decorative (breeding of mostly domestic dogs of original forms, companion dogs). Thus, the study of the history of cynology will allow more extensive use of the capabilities of dogs in the modern cynological service.