Chemotherapy in dogs and cats

Chemotherapy in dogs and cats is primarily indicated for animals with systemic (e.g., lymphoma, leukemias) or metastatic neoplasms, although it can also be used for the management of nonresectable, chemoresponsive neoplasms that have historically proved refractory to radiotherapy or hyperthermia (primary chemotherapy). It can also be used as an adjuvant treatment after partial surgical debulking of a neoplasm (e.g., partial excision of an undifferentiated sarcoma) and is indicated for the control of micrometastatic disease after the surgical excision of a primary neoplasm (e.g., cisplatin, carboplatin or doxorubicin therapy after limb amputation in dogs with osteosarcoma; VAC after splenectomy for dogs with hemangiosarcoma).

Chemotherapy can also be administered intracavitarily in dogs and cats with malignant effusions or neoplastic involvement in the cavity/area in question (e.g., intrathecally administered cytosine arabinoside in dogs and cats with pleural carcinomatosis).
As a general rule, chemotherapy should not be used as a substitute for surgery, radiotherapy, or hyperthermia; nor should it be used in animals with severe underlying multiple-organ dysfunction because this increase the risk of systemic toxicity.