Clinical Presentation and Diagnostic Challenges of Congenital Thoracoabdominal Wall Defects in Dogs: Insights from a Case Series and Literature Synthesis.

Congenital thoracoabdominal wall defects in dogs are uncommon and challenging to classify due to their overlapping anatomical and developmental features. This study analyzes three original canine cases alongside 17 published cases to clarify the relationships among Cantrell syndrome (CS), amniotic band syndrome (ABS), and body stalk anomaly (BSA). All of the original cases exhibited thoracoabdominal involvement with variations in umbilical cord morphology and associated anomalies. A comparative analysis revealed that these conditions form a syndromic continuum rather than distinct entities, influenced by the timing and mechanism of embryonic disruption. Early developmental insults were associated with multisystem malformations resembling CS or BSA, whereas later vascular disruptions produced more localized defects, such as gastroschisis. Umbilical cord morphology emerged as a key diagnostic discriminator across cases. Based on these findings, we developed an anatomically driven diagnostic decision tree to support clinical evaluation when information is incomplete. This study emphasizes the importance of integrating embryologic context with anatomical assessment and identifies significant gaps in molecular and genetic data. A developmental continuum model offers a more flexible, clinically meaningful framework for diagnosing congenital body wall defects in dogs.