Because of their high incidence and diverse behavior, canine mammary tumors (CMTs) are one of the most commonly diagnosed neoplasms in female dogs and provide a serious health risk. The epidemiological characteristics, pathological categories, clinical manifestations, diagnostic techniques, and therapeutic approaches related to CMTs are described in this review. Age, breed, hormonal state, timing of spaying, and obesity are risk factors for almost half of these tumors, which are malignant. While molecular markers are increasingly used to guide prognosis and therapy selection, histopathology is still the gold standard for diagnosis. The main treatment option is surgical excision, which is frequently complemented by hormone therapy, chemotherapy, and newer immunotherapeutic techniques. The prognosis for malignant cases is still uncertain despite advancements in diagnosis and therapy, which emphasizes the necessity of individualized approaches as well as further research into biomarkers and targeted medicines.