Before joining the Welsh Government, Gavin worked as a veterinary investigation officer based in Carmarthen and before that he was a researcher in bacterial diseases in sheep.
Cyn ymuno â Llywodraeth Cymru, bu Gavin yn gweithio fel Swyddog Archwilio Milfeddygol yng Nghaerfyrddin a chyn hynny roedd yn ymchwilydd clefydau bacteria mewn defaid.