Canine sciatic and gluteal lymph nodes can be identified with computed tomography

Sciatic and gluteal lymph nodes are present in multiple veterinary species, but these lymph nodes are explicitly stated to be absent in dogs. However, structures compatible with lymph nodes have been identified in the appropriate locations in some canine patients undergoing abdominopelvic CT, and the presence of such lymph nodes may have prognostic and therapeutic ramifications in canine patients with abdominopelvic disease. The purpose of this study was to determine the prevalence and characteristics of sciatic and gluteal lymph nodes in dogs on CT. Images of 121 dogs that underwent abdominopelvic CT between September 1, 2020 and December 31, 2020 were reviewed retrospectively by two readers to produce a consensus opinion regarding the presence or absence of sciatic and gluteal lymph nodes. Lymph nodes that were present were measured. Unilateral or bilateral sciatic lymph nodes were present in 19 of 121 dogs (prevalence 15.7%), and bilateral gluteal lymph nodes were identified in one of 121 patients (prevalence 0.8%). Recognition of the presence of sciatic and gluteal lymph nodes in some canine patients may play an important role in the staging of abdominopelvic disease, both in the identification of disease spread and in therapeutic planning.