Case summary: A 3-year-old male neutered domestic shorthair cat sustained a severe sacrococcygeal luxation post-motor vehicle trauma. Six days post-trauma, a fluid-filled swelling was noticed over the caudoventral abdomen and inguinal regions. Needle aspiration, closed suction drain placement and debridement with subcutaneous tacking were all attempted but failed to resolve the continued accumulation of serosanguinous lymphocyte-rich fluid in the subcutaneous pocket. Clinical resolution was ultimately achieved after surgical debridement and omentalisation of the lesion.
Relevance and novel information: Morel-Lavallée lesions are post-trauma closed soft tissue degloving injuries described infrequently in people. The avulsion of subcutaneous tissue from deep muscle fascia results in the accumulation of haemolymph and necrotic fat, which can persist for several days to months after the inciting incident. In people, they are commonly seen in the proximal thigh. This article proposes the existence of Morel-Lavallée lesions in cats.