Case Report: Multiple mammary carcinomas in a young dog with estrus-associated hyperglycemia: clinicopathological findings and glycemic normalization after ovariohysterectomy.

Mammary tumors are among the most common neoplasms affecting female dogs and are typically diagnosed in middle-aged or older animals. The occurrence of malignant mammary tumors in very young dogs is uncommon and may present diagnostic and clinical management challenges. This case report describes a young female dog presenting with multiple mammary nodules accompanied by persistent hyperglycemia detected approximately one to 2 weeks before the onset of estrus. Clinical examination, hematological and biochemical testing, cytological evaluation, surgical excision of the mammary lesions, and histopathological analysis were performed. Histopathology confirmed the presence of multiple mammary carcinomas with different histological patterns. Despite surgical removal of the tumors, blood glucose concentrations remained elevated. Two weeks later, the patient underwent ovariohysterectomy, after which glycemic values gradually decreased and returned to normal within the following weeks. The temporal association between reproductive hormonal status and the observed metabolic alteration suggests a possible hormone-related insulin resistance rather than a direct metabolic effect of the tumors themselves. This case highlights the potential interaction between mammary neoplasia, reproductive hormonal status, and glucose metabolism in dogs and emphasizes the importance of comprehensive clinical and metabolic evaluation in young patients presenting with mammary tumors.