David graduated from Manchester University in 1985 with a BSc Honours in Biochemistry and from Edinburgh University in 1989 with a PhD in biochemistry on the effects of cholera toxin on intracellular signalling in enterocytes. His first post-doctoral position was a 4-year project at the MRC Human Genetics Unit in Edinburgh on the tissue localisation of the product of the Cystic Fibrosis gene, the Cystic Fibrosis Transmembrane Conductance Regulator.
He moved to Moredun in 1993, taking a post within Moredun Animal Health (now Moredun Scientific) on a commercially-funded project developing vaccines for controlling nematode infections. In 1994 he was appointed as a postdoctoral scientist on an EU-funded Third Framework project developing better detection systems for chlamydial infections of farm livestock and zoonotic infections of man. In August 1997 he was appointed Head of the Molecular Chlamydiology group at Moredun, and as Molecular Biology Theme Leader for the Institute in 2003. He is currently a Senior Principal Research Scientist, leading a group investigating the pathogenesis and control of chlamydial infections in ruminants and also Head of Diagnostics. Since 2002 he has been responsible for the OIE (World Organisation for Animal Health) chapter on Enzootic Abortion of Ewes (Ovine Chlamydiosis) and since 2008 he has been scientific editor for Research in Veterinary Science.