[Squamous cell carcinoma of the claw matrix in a cow].

Clinical, radiographic, gross-pathological and histological findings in a squamous cell carcinoma of the claw matrix in a three-year-old Simmental cow are described. The cow showed severe lameness of the right foreleg. Radiological examination revealed a large osteolytic focus in the medial distal phalanx. The tentative clinical diagnosis of apical pedal bone necrosis was followed by amputation and pathological examination of the claw. The horn capsule showed no lesions. Pathological examination revealed soft consistency of pedal bone and the cut surface showed a yellowish crumbling material, which had replaced most of the pedal bone. Histologically, infiltration and osteolysis of distal pedal bone by a squamous cell carcinoma was ascertained. This claw tumor has not been reported until now. Clinically, it resembles apical pedal bone necrosis and therefore should be included in the differential diagnosis.