The theme of Dr. Harding's research is emerging and re-emerging diseases of pigs. Earlier in his career, he co-discovered porcine circovirus type 2, and characterized its impact and epidemiology in affected farms. More recently, his research has focused on other novel diseases and syndromes, most notably "Brachyspira hampsonii" colitis and periweaning failure-to-thrive syndrome (PFTS).
In addition, his current research aims to understand mechanisms associated with severity of reproductive PRRS, as well investigating prenatal immunologic programming associated with intrauterine growth retardation. Dr. Harding was awarded the Pfizer Animal Health Award for Research Excellence in 2010.