Common Diagnoses from Surgical Biopsies and Investigation of Leporipoxvirus in Pet Rabbits (Oryctolagus cuniculi) in Taiwan

This study investigated common diagnoses from surgical biopsies of domestic rabbits (<i>Oryctolagus cuniculi</i>) in Taiwan and examined the role of leporipoxvirus in tumor pathogenesis. Biopsy specimens from 70 rabbits collected between 2014 and 2023 were retrospectively analyzed, yielding 85 diagnoses. Polymerase chain reaction (PCR) was performed to detect leporipoxvirus in formalin-fixed, paraffin-embedded tissues diagnosed with fibroma, fibrosarcoma, or myxosarcoma. The most commonly affected systems were the integumentary (<i>n</i> = 41) and reproductive (<i>n</i> = 36) systems. Common integumentary tumors included fibrosarcomas (<i>n</i> = 12), trichoblastomas (<i>n</i> = 8), mammary gland tumors (<i>n</i> = 5), and fibromas (<i>n</i> = 4). In the reproductive system, the most common lesions were uterine adenocarcinomas (<i>n</i> = 16), uterine endometrial cystic hyperplasia and hypertrophy (<i>n</i> = 5), and uterine adenomyosis (<i>n</i> = 4). The 15 cases of fibroma, fibrosarcoma, and myxosarcoma were tested for leporipoxvirus using PCR. No viral sequences were detected in these tumors. This study identified the common diagnoses from rabbit biopsy specimens and found no leporipoxvirus infection in samples of fibrosarcoma and fibroma. This is the first study on tumors in pet rabbit biopsies and the first in Taiwan to investigate leporipoxvirus infection, providing valuable insights for future diagnosis and management.