Companion animals, such as dogs and cats, have gained considerable attention in translational medicine due to their potential as models for human diseases. The use of these animals in research has opened new avenues for developing treatments that can benefit both human and veterinary patients, aligning with the One Health approach. Unlike traditional laboratory models like mice, rats, and rabbits, companion animals naturally develop diseases that closely mirror those in humans, including but not limited to diabetes, aging, cancer, and neurological disorders, making them particularly valuable in translational research. Recent advances have highlighted the role of companion animals in enhancing the effectiveness of novel therapies during clinical trials, as they are exposed to diverse environmental and lifestyle factors similar to those experienced by humans. However, the integration of companion animals into translational medicine presents challenges, particularly in terms of collaboration between veterinary and human medicine, where terminology differences in anatomy, clinical terminology, and animal classification can lead to miscommunication. In conclusion, these findings underscore the need for better implementation of the One Health approach by uniting the fragmented collaboration between veterinarians and doctors through interdisciplinary training and fostering unified efforts across both fields, with experts from various disciplines contributing their specialized knowledge in clinical practice and research.