[2][3][4] She was appointed Chief Inspector of the Home Office unit for Animals in Science Regulations in 2007 and remained in that post until standing down in 2016.
[9][10] Clark is a policy advisor for the Royal Society of Tropical Medicine and Hygiene.
[6] Clark was the first president, in 2006, of the International Association of Colleges of Laboratory Animal Medicine.
[13] Clark was employed as Vice-President of Worldwide Comparative Medicine for Pfizer, and runs her own company, JMC Welfare International.
[9][15][16] She was made an honorary fellow of the British Pharmacological Society in 2016, "for her sustained leadership in the regulation of animal research".