Hematopoietic tumors such as lymphoma are common in cats, accounting for nearly one-third of all cancer in this species. Lymphoma affects all breeds, including Siamese and Oriental Shorthairs, and causes significant impact on quality of life as well as mortality. The incidence of feline lymphoma is increasing, with more and more cats developing this deadly but treatable cancer every year. The use of L-asparaginase (Elspar®), an effective chemotherapeutic agent, is limited in cats because of expense. The drug is packaged in human-sized doses, and unused drug must be discarded resulting in the majority of the drug being wasted in cats. Similar to other drugs, L- asparaginase may retain enzymatic and biologic cell-killing abilities against tumor cells after refrigeration and/or freezing. The goal of this research is to establish a scientific basis for the practice of long-term cold storage of L-asparaginase. This may provide multiple doses from one vial, decreasing costs for pet owners and improving medical care for cats with lymphoma.