Background: The overweight/obesity in dogs is defined as a condition of abnormal fat accumulation or, beyond that, a multifactorial condition involving excessive fat accumulation along with different factors (insufficient physical activity, genetics (breed), metabolism, the microbiome, etc.). Preclinical obesity conditions increases the risk of progressing to clinical obesity and developing obesity-associated diseases such as type 2 diabetes, cardiovascular disease, certain cancers, and mental disorders. Objectives: This study aimed to determine the weight-loss effects of liraglutide in dogs that do not engage in sufficient exercise, are fed table scraps, and develop obesity owing to aging. Animals: In this study, 21 senior Golden Retriever dogs were divided into three equal groups. Methods: Group 1 was considered healthy and consisted of dogs within the range of ideal body live weight and body condition scores, and fed dry commercial dog food at the amount of their daily metabolizable energy requirements. Group 2 included seven senior dogs with obesity fed commercial dry food adjusted for their daily metabolizable energy requirements. Group 3 comprised seven senior dogs with obesity fed commercial dry food adjusted for their daily energy requirements and concurrently treated with subcutaneous liraglutide at a dose of 1.2 mg/dog. The trial lasted for 40 days. Results: Liraglutide treatment resulted in a decrease in body condition score (BCS) and body weight by day 40, although the reduction in body weight (13.27 %) did not reach statistical significance. Liraglutide significantly lowered cholesterol and triglyceride levels, and appetite tests revealed a marked suppression of food intake over consecutive days in treated dogs. Conclusions and clinical importance: Liraglutide treatment may offer a viable option for treating obesity in dogs, and could potentially be used as a new anti-obesity drug in canines. Future long-term and detailed trials of liraglutide in dogs with obesity could facilitate its effective use in the field.