Les has spent most of his professional life in government veterinary service (1979 to 2016), including within the Welsh Government as a veterinary adviser.
Mae Les wedi treulio rhan fwyaf o’i fywyd proffesiynol o fewn gwasanaeth milfeddygol y llywodraeth (1979 i 2016), gan gynnwys o fewn Llywodraeth Cymru fel Cynghorydd Milfeddygol.