Donald graduated from Massey University with a Bachelor of Veterinary Science in 1982. After a few years of working in dairy practice in the North Island he completed post graduate studies at Cornell University (USA) specialising in diagnostic pathology. In 1991 he became a Diplomate of the American College of Veterinary Pathologists.
In 1998 he was a founding shareholder and director of Labworks, the first privately owned veterinary diagnostic laboratory in the South Island. In 2001 Labworks was sold to Gribbles Veterinary Pathology, an ASX listed company.
In 1996 Donald and Jose established Selwyn Rakaia Vet Services in Dunsandel which now employs about 20 staff servicing about 140 dairy farms in Canterbury.
Donald and Jose are also shareholders in Callura Dairies, a 2000 cow dairy farm near Culverden. Their recognition of the increasing complexity of dairy farming and the growing need for expertise in many areas has lead to an investment in DFMS.