Oral chemotherapy agents in cats: clinical uses, administration and side effects

PRACTICAL RELEVANCE: Cancer is a very common disease in cats, and many feline patients will require chemotherapy as part of their treatment plan, either as a sole agent or as part of multimodality therapy. Although some general practitioners might be reluctant to undertake injectable chemotherapy, oral chemotherapy may feel like a more acceptable treatment option to manage in practice. CLINICAL CHALLENGES: The small body size of many cats means that tablet sizes made for the human market are less appropriate, which creates dosing challenges. The administration of oral medication can also be a challenge in some cats. AUDIENCE: This review is aimed at general practitioners and other clinicians undertaking chemotherapy of feline cancer patients. It summarises the oral medications available for use, their therapeutic indications, dosing strategies, side effects, and health and safety aspects. EVIDENCE BASE: The review includes information from past and recent veterinary literature on the use of oral cytotoxic drugs in cats. PATIENT GROUP: Oral cytotoxic medications may be used in cats for a variety of tumour types, of which haematopoietic tumours, such as lymphoma, would be the most common.