目的 对前来就诊的高龄京巴犬腹部肿物进行有效诊治，以期为类似病例的研究和诊治提供参考。 方法 采用临床检查、血常规检查、血液生化检查、病理组织学方法进行诊断，并结合诊断结果进行综合性治疗。 结果 该患犬诊断为乳腺肿瘤。通过手术成功切除乳腺肿瘤，病理学诊断为高级别导管内原位癌。术后进行系统治疗，3个月后复发，DR影像显示为癌转移。 结论 平时应多观察犬的身体状况，发现异样及时到正规动物医院就诊，乳腺肿瘤早发现、早治疗，才能得到良好的治疗效果和较高的治愈率。

Objectives Effective diagnosis and treatment of abdominal masses in an elderly Pekingese come for medical consultation was conducted to provide reference for the research and diagnosis of similar cases. Methods The clinical examination, routine and biochemistry examination of blood, and histopathological methods were used to diagnose the elderly Pekingese. Comprehensive treatments were carried out based on the results of diagnosis. Results The patient Pekingese was diagnosed with breast tumor. The breast tumor was successfully removed through surgery, and the result of pathological diagnosis showed that the breast tumor was high-grade ductal carcinoma in situ. Systematic treatment was performed after surgery, and recurrence occurred 3 months later. The result of DR imaging showed that it was cancer metastasis. Conclusions It is important to observe the physical condition of dogs regularly and seek medical consultation promptly at a reputable animal hospital if any abnormalities are detected. Early detection and treatment of breast tumors are essential for achieving good effect of treatment with a higher rate of recovery.