[3] Halliwell studied veterinary science at Cambridge University graduating in 1961, and subsequently receiving his doctorate there in 1973.
He served as Dean of Veterinary Science at Edinburgh University (at the Dick Vet School) for two periods, from 1990 to 1994 and for the academic year 2001–02.
[3] In 1989 he was President of the world's first conference on Veterinary Immunology in Dijon in France.
[5] In 2012 he was awarded the Hugo Schindelka medal by the World Association for Veterinary Dermatology (WAVD) in Vancouver, in recognition of a lifetime of excellent work in the field of veterinary dermatology.
[7] Halliwell was one of twenty "shadow portraits" created in the Summerhall building of the college, depicting former Principals.