Chemotherapy for solid cutaneous tumours

Solid cutaneous tumours, including sarcoids, melanomas and squamous cell carcinomas, present significant therapeutic challenges in equine practice, particularly when surgery is not feasible or carries unacceptable risks. In this lecture, I will explore chemotherapy as an alternative or adjunct to surgery, focusing on local drug delivery to maximise tumour exposure while minimising systemic adverse effects. You will learn about topical and intratumoural chemotherapy, including cisplatin delivered in oily emulsions, biodegradable sustained-release beads and electrochemotherapy. I will outline the mechanisms, indications, advantages and limitations of these approaches, highlighting how tumour size, location and tissue depth influence treatment selection. Recent advances in electroporation technology will also be discussed, including developments aimed at improving safety and potentially enabling treatment in standing, conscious horses. By the end of the lecture, you will have a clearer understanding of current chemotherapy options for equine cutaneous tumours and the practical considerations involved in selecting appropriate treatments to improve clinical outcomes.

• • Understand the principles of chemotherapy for equine cutaneous tumours and its role as an alternative or adjunct to surgical excision.
• • Identify the indications, advantages and limitations of topical and intratumoural chemotherapy, including cisplatin emulsions and biodegradable sustained-release beads.
• • Explain the principles of electrochemotherapy, including drug delivery, electrode selection and factors influencing treatment efficacy and safety.
• • Evaluate how tumour size, location and tissue depth, alongside emerging advances in electroporation technology, influence treatment selection and clinical decision-making.