1990-1991: Assistant lecturer, Department of Applied Sciences, Kenya Polytechnic: Nairobi
1991-1993: Assistant Research Officer, Kenya Trypanosomiasis Research Institute (KETRI), Chemotherapy Division.
1993-1996. Research Officer, Kenya Trypanosomiasis Research Institute (KETRI), Chemotherapy Division.
1996-1997. Senior Research Officer: Kenya Trypanosomiasis Research Institute (KETRI), Chemotherapy Division.
1997-2000. Lecturer Egerton University, Department of Biochemistry and Molecular Biology, Njoro Campus
2000 to 2008. Senior Lecturer, Egerton University, Department of Biochemistry and Molecular Biology, Njoro, Campus
2008-to 2013. Associate Professor, Egerton University, Department of Biochemistry and Molecular Biology, Njoro Campus.
2013 to date. Full Professor, Egerton University, Department of Veterinary Pathology, Microbiology and Parasitology, Faculty of Veterinary Medicine and Surgery, Njoro Campus.