Monocephalus dipygus in a 4-month-old mixed-breed puppy: clinical, radiographic, ultrasonographic, karyotyping and surgical intervention

Congenital anomalies are rare in veterinary medicine, and their aetiology, development, clinical presentation, and management remain poorly understood. This study documents a rare case of multiple congenital anomalies occurring simultaneously in a single individual. We present a comprehensive analysis of a 4-month-old mixed-breed puppy diagnosed with caudal duplication (monocephalus dipygus), integrating clinical, radiographic, ultrasonographic, cytogenetic findings, and surgical intervention. The puppy exhibited several external abnormalities, including a supernumerary limb, a single tail, two penises, and two distinct scrotal sacs. Radiographic examination revealed additional metatarsal and phalangeal bones in the supernumerary limb. Ultrasonography and exploratory laparotomy further identified two bladders, a single prostate, and bifurcated ureters, each connecting to a kidney. Cytogenetic analysis was conducted to investigate potential chromosomal abnormalities underlying these congenital anomalies, as we hypothesized that these malformations might be linked to chromosomal aberrations. The successful surgical removal of the supernumerary limb significantly improved the dog's mobility. Notably, since each bladder was independently connected to a kidney, surgical intervention in the genitourinary system was avoided to prevent potential impairment of urinary function. This case highlights the complexity of congenital anomalies in canines and emphasizes the importance of a multidisciplinary approach to their diagnosis and management.