Meet Our Team

Associate Professor Anne Peaston

BVSc, PhD, DACVIM (Oncology), FANZCVS (Oncology)
Clinical Lead
Associate Professor Small Animal Medicine

Anne Peaston is an international cancer expert with experience across veterinary clinical medicine and biomedical research. Her garden at home is an abundance of Australian native plants to attract vertebrate and invertebrate wildlife, while minimising her cats' access, to their displeasure!

Dr. Sita Withers

BVSc(Hons), PhD, DACVIM(Onc)
Senior Lecturer

Dr. Sita Withers joined our Small Animal Oncology Service in March 2024. 

After graduating with a veterinary degree from the University of Melbourne in 2008, Sita practiced in Australia for two years before moving to California to undertake a medical oncology residency at the University of California Davis (UC Davis). She became a board-certified specialist in medical oncology (DACVIM(Onc)) in August, 2014. During her residency, she developed a keen interest in cancer research and went on to pursue a PhD in Integrative Pathobiology. She then spent 5 years at Louisiana State University (LSU) as a tenure-track Assistant Professor of Medical Oncology. She has been invited to present her research and give continuing education at international conferences in both the United States and China, and is thrilled make her way back to Australia to join the faculty at The University of Adelaide. When she's not at work she enjoys hoarding plants, jogging, swimming, practicing yoga, traveling and hanging out with her two dogs and two cats.

Dr Olaf Schaaf

Olaf Schaaf has been a specialist small animal surgeon registered both in Australia and Europe. He completed his residency training at Murdoch University, Perth in 2009 and attained became a Diplomat of the European College of veterinary Surgeon in 2011.  He worked in private referral practise in the Perth and the Sunshine Coast, before accepting the challenge of help start up the Adelaide University Vet school in 2012. He enjoys all aspects of dog and cat surgery and accepts surgical referrals for soft tissue, orthopaedic and spinal surgery. He has a keen interest in all things orthopaedic including: fracture repairs, growth deformities, ligamentous injuries, cruciate disease, patella luxation, arthroscopy as well as oncology (cancer) surgery. When he is not helping animals getting a better quality of life in the clinic or teaching up and coming veterinarians, you'll find him spending time with his daughters; crazy Jack Russell Terrier, sweet Staffy x Dachshund or relaxing with his 2 Burmese cats.

Dr Anthony Nicholson

While he's now anaesthetising mice to elephants and everything in between; Anthony's interests were originally in the respiratory anatomy and physiology of marine mammals. In his spare time, he enjoys cat-herding (Gordon-Bennett, Beanie, Perch and Freddy), Pippa the dog, photography, music and cooking.

Dr Peter Hutchison

Peter’s interests lie in emergency medicine, small animal surgery and exotic pets. He currently spends his time with domestic short-haired cat Donut and Ixy the kelpie. His past acquaintances include Ginger the axolotl; Thomas the tortoise and Jeffery Gary Williams the giant panda snail.

Dr Greg Riessen

After having gained experience in both mixed and small animal practice both here and overseas in the UK for 10 years, Greg developed a keen interest in small animal emergency and critical care whilst working for the UK's largest provider of emergency care, Vets Now.  In 2014 Greg relocated back to his native hometown Adelaide with his wife and two kids before joining the team at Companion Animal Health Centre in 2018.  Greg is currently working towards gaining his memberships in Emergency and Critical Care.