Background <p>Improvements in veterinary medicine have markedly prolonged the lifespan of zoo animals. With this longevity, conditions once seldom recognized, such as neoplastic diseases, are increasing. Nevertheless, multiple primary malignant tumors (MPMTs) remain rarely reported and pose substantial diagnostic challenges in veterinary practice. Here, we report the first documented case of synchronous uterine leiomyosarcoma and pulmonary adenocarcinoma in a meerkat (Suricata suricatta), underscoring the importance of thorough diagnostic evaluation in zoo animal management.</p> Case presentation <p>An 11-year-old captive female meerkat presented with progressive abdominal distension. Clinical examination and diagnostic imaging revealed significant uterine enlargement and multiple pulmonary nodules. Exploratory laparotomy and ovariohysterectomy were performed, and a 5-cm uterine mass was removed. Grossly, the mass showed extensive multifocal necrosis, and leiomyosarcoma was diagnosed through histopathologic examination. Following the diagnosis of uterine leiomyosarcoma, the pulmonary nodules were presumed to be metastatic. Given their multilobar involvement and the patient’s advanced age, invasive diagnostic procedures were not performed, and palliative care was provided. The meerkat survived for 15 months in stable condition. Postmortem examination revealed that the pulmonary nodules were primary adenocarcinomas, thereby confirming the synchronous occurrence of two distinct primary malignancies.</p> Conclusions <p>This case emphasizes the importance of timely biopsy and thorough postmortem examination for distinguishing multiple primary malignancies from metastatic disease. With the increasing longevity of zoo animals, geriatric health management strategies including routine screenings and comprehensive diagnostics are essential for clinical decision-making and animal welfare.</p>