John graduated from the University of Queensland in 1988. He worked in general practice in Brisbane for 18 months before travelling to the UK in 1990, where he worked in small animal practice for the next 11 years. He was a clinical assistant in dermatology at the Animal Health Trust from 1998 to 2001. In 2001 John set up North Kent Referrals, a multi-disciplinary referral practice in the south of England, and he owned and ran the practice until its sale in 2012.

John is a registered specialist in Veterinary Dermatology. He holds the RCVS Certificate in Veterinary Dermatology, is a member of the Australian College of Veterinary Scientists (MANZCVS) by examination in small animal medicine and is a diplomate of the American College of Veterinary Dermatology. John is a past President of the British Veterinary Dermatology Study Group. He is Adjunct Associate Professor at the University of Queensland, where he provides the dermatology referral service.

Following his return to Brisbane in 2013, John joined the team at Dermatology for Animals. His clinical interests include the management of allergic skin disease in dogs, immune mediated skin disorders, and all aspects of feline and equine dermatology. John has regularly presented on the subject of veterinary dermatology to veterinary surgeons and nurses all over the world.