Acute compartment syndrome in the pelvic limb of a cow following biopsy of a skeletal muscle-associated hemangiosarcoma.

Case Description: A 6-year-old Holstein cow was examined because of chronic lameness and swelling near the stifle joint of the left pelvic limb.

Clinical Findings: A mass was palpated in the soft tissues lateral to the proximal aspect of the left tibia. Multiple attempts to obtain a biopsy specimen of the mass resulted in acute compartment syndrome of the femoral compartment (tensor fasciae latae and biceps femoris muscles) and lateral tibial compartment (cranial tibial and peroneus tertius muscles) with associated sciatic nerve paralysis.

Treatment And Outcome: Surgical decompression via tensor fasciae latae and biceps femoris incision resolved the sciatic nerve paralysis. On the fifth day following surgery, the cow began to develop signs of increased respiratory effort. Thoracic radiography revealed a pulmonary metastatic micronodular pattern. The cow was euthanized because its condition deteriorated. Metastatic hemangiosarcoma was confirmed at necropsy, and the primary tumor was the mass that was lateral to the tibia and within the biceps femoris muscle.

Clinical Relevance: Hemangiosarcoma should be considered a differential diagnosis for lameness in cattle when no orthopedic cause can be identified. Close patient surveillance is strongly recommended in the event that a vascular tumor is present because catastrophic consequences are possible. To our knowledge, this is the first report of acute compartment syndrome in a pelvic limb of a bovine patient and the only report of hemangiosarcoma in the skeletal muscle of cattle.