The clinical, ultrasonographic, radiographic, cytologic and bacteriologic findings, diagnosis and surgical treatment of two heifers with septic metacarpal physitis (type-1 osteomyelitis) and concurrent serofibrinous arthritis of the metacarpophalangeal (MCP) joint are described. Osteomyelitis likely occurred by haematogenous spread following bronchopneumonia in one heifer and developed post-traumatically in the other. In both patients, ultrasonographic examination using the 7.5 MHz linear probe showed moderate effusion of the palmar and dorsal MCP joint pouches and highly irre-gular bone contours with depression and periosteal new bone formation at the metacarpal growth plate. Radiographs showed an extensive radiolucent area with poorly defined margins at the level of the metacarpal growth plate. Surgical treatment was carried out under sedation and regional intravenous anesthesia and involved meticulous debridement of the osteomyelitic lesion of the meta-carpal growth plate combined with arthrotomy of the MCP joint and repeated lavage of the bone cavity and joint. Successful outcomes were achieved by combined use of systemic and locoregional antibiotics, NSAIDs, temporary external coaptation and adequate housing.