RESUMEN
CASE HISTORY: A 1-year-old German Shepherd dog presented for delayed onset of a traumatic, dorsal diaphragmatic hernia of the pars lumborum. CLINICAL FINDINGS AND TREATMENT: Herniorrhaphy via a ventral midline celiotomy (with and without a paracostal extension) were unsuccessful and the hernia recurred. The hernia was successfully repaired using a single lateral paracostal surgical approach. This approach provided excellent exposure and should be considered for dorsal pars lumborum diaphragmatic hernia repairs. DIAGNOSIS: Dorsal diaphragmatic hernia of the pars lumborum. CLINICAL RELEVANCE: Whilst uncommon, tears to the dorsal aspect of the diaphragm should be considered as well as the more common radial or circumferential pars costalis tears. Pre-operative computed tomographic imaging can identify the exact location of the hernia in order to allow the best surgical approach to be determined. A lateral paracostal approach should be considered as an alternative to a ventral midline celiotomy with or without paracostal extension for repair of dorsal diaphragmatic hernias affecting the pars lumborum, as it provides excellent exposure. A single lateral paracostal approach has not been reported previously for diaphragmatic hernia repair in dogs.