In this short lecture we will discuss some of the ancillary tests that are available as additional tools to cytology in the diagnostic workup of canine lymphoma. We will briefly review the principles of immunocytochemistry (ICC), flow cytometry, and clonality testing (PARR), and which type of information each of these tests provide. We will discuss which ancillary test may be most appropriate to confirm a cytological suspicion, or to further characterise a lymphoma based on initial cytological findings, and review sample requirements.