T. J. Smith, N. M. Girard, J. O'Riordan, N. Fitzpatrick Veterinary and Comparative Orthopaedics and Traumatology 2009 22 4 332-335 In this report, a case of cranial cruciate ligament (CrCL) rupture treated by tibial plateau levelling osteotomy (TPLO), in a 36-month-old male breeding alpaca, is described. The alpaca was presented with the complaint of acute onset of right pelvic limb lameness. The findings of our clinical and radiographic examinations were consistent with CrCL insufficiency of the right stifle joint. The right tibial plateau angle measured prior to surgery was 19°. A TPLO was performed and this eliminated cranial tibial thrust. Culture of a swab taken from the surgical site prior to wound closure was positive for Pseudomonas aeruginosa . Enrofloxacin was administered parenterally for two weeks postoperatively. There were not any clinical signs of infection noted. Outcome assessments included veterinary examination (two and six weeks) and owner assessment (28 months). At two weeks the animal walked with a grade 2/5 lameness, and at six weeks radiographic examination showed progression of bone healing at the site of tibial osteotomy. A return to full breeding fitness occurred by eight weeks after the surgery. The alpaca remained free from lameness 28 months later, according to the owner.