Jooske IJzer graduated as veterinarian at Utrecht University in 1995. She worked in mixed practice until 1997, and succesfully finished the residency in veterinary pathology in 2002. She finished her PhD at Utrecht University, the Netherlands, titled "Liver fibrosis and regeneration in dogs and cats: an immunohistochemical approach" in 2008. Afterwards, her research output was related to her diagnostic work as zoo- and wildlife veterinary pathologist at Utrecht University.